Today is a usualwas and ordinary day. Today was an ordinary day.

"usual and ordinary" is an awkward phrasing. Also, this seems to be in the past, so "was" is more appropriate

Today iwas a usual and ordinary day. Today was a usual and ordinary day.

This is now past tense as you are recounting a story from your day => was A bit more natural: Today was a typical, ordinary day.

I headed to the gym to work out my chest and abs today after I walked my dog in the morning. I headed to the gym to work out my chest and abs today after I walked my dog in the morning.

I headed to the gym to work out my chest and abs today after I walked my dog in the morning. I headed to the gym to work out my chest and abs after I walked my dog in the morning.

No need to repeat "today" as it's understood from the previous sentence. A bit more natural: I headed to the gym to work out my chest and abs after walking my dog in the morning.

I headed to the gym to work out my chest and abs today, after I walked my dog in the morning. I headed to the gym to work out my chest and abs, after I walked my dog in the morning.

Remember the past tense. Repeating today again after the last sentence isn't need

I cookedmade spicy instant noodles and fried eggs after I wenwhen I got back home. I made spicy instant noodles and fried eggs when I got back home.

More natural

EAn embarrassing moment today An embarrassing moment today

Embarrassing mMoment tToday Embarrassing Moment Today

Title capitalization rules

I wanted to use the chest adduction machine that can build up the middle part of my chest muscle, but unfortunately there were too many gentlemenpeople waiting for the machine, so I left. I wanted to use the chest adduction machine that can build up the middle part of my chest muscle, but unfortunately there were too many people waiting for the machine, so I left.

I wanted to use the chest adduction machine that can build upworks the middle part of my chest muscle, but unfortunately there were too many gentlemen waiting for the machine, so I left. I wanted to use the chest adduction machine that can works the middle part of my chest, but unfortunately there were too many gentlemen waiting for the machine, so I left.

"Gentleman" is being extremely polite (which is fine), but if you wanted to be more casual, you could say "other guys."

I wanted to use the chest adduction machine that can build up the middle part of my chest muscles, but unfortunately there were too many gentlemenpeople waiting for the machine, so I left. I wanted to use the chest adduction machine that can build up the middle part of my chest muscles, but unfortunately there were too many people waiting for the machine, so I left.

I actually didn't know what the machine was called, I had to google adduction to see what it meant myself :)

After the exercise, I went to the supermarket just next to the gym that I would walk by on the way back to home, and I bought a bunch of fruits like blueberries, strawberries, and even grape tomatoes, since I started my healthy diet to make my tummywaist smaller. After the exercise, I went to the supermarket just next to the gym that I walk by on the way back home, and I bought a bunch of fruits like blueberries, strawberries, and even grape tomatoes, since I started my healthy diet to make my waist smaller.

“tummy” sounds very cute. Something like “waist” is more fitting with the rest of your writing.

After the exercise, I went to the supermarket just next to the gym that I would walk by on the way back to home, and. I bought a bunch of fruits like blueberries, strawberries, and even grape tomatoes, since I started my healthy diet to make my tummy smaller. After the exercise, I went to the supermarket just next to the gym. I bought a bunch of fruits like blueberries, strawberries, and even grape tomatoes, since I started my healthy diet to make my tummy smaller.

After the exerciseing, I went to the supermarket just next to the gym that I would walk bypass on the way back to home, and I bought a bunch of fruits, like blueberries, strawberries, and even grape tomatoes, since I started myas part of my new healthy diet to make my tummy smaller. After exercising, I went to the supermarket next to the gym that I pass on the way back home and bought a bunch of fruit, like blueberries, strawberries, and even grape tomatoes, as part of my new healthy diet to make my tummy smaller.

"The exercise" makes it sound like you did one form of exercise only. "Tummy" is a cute word that kids and women would use, but men would typically avoid (in case you care about that; I don't, personally).

After the exercise, I went to the supermarket just next to the gym that I would walk by on the way back to home, and I bought a bunch of fruits like blueberries, strawberries, and even grape tomatoes, since I started my healthy diet to make my tummystomach smaller. After the exercise, I went to the supermarket just next to the gym that I walk by on the way back home, and I bought a bunch of fruits like blueberries, strawberries, and even grape tomatoes, since I started my healthy diet to make my stomach smaller.

"tummy" is kind of a childish/cutesy phrasing and doesn't fit with the tone of the rest of the piece.

I did not want to cook the instant noodles, because they will make me fat. I did not want to cook the instant noodles because they will make me fat.

I did not want to cook the instant noodles, because they make me fat. I did not want to cook the instant noodles because they make me fat.

I was just too lazy to make other food for lunch. I was just too lazy to make other food for lunch.

Better: I was just too lazy to make something else for lunch.

Then I went tout for work after taking a nap. Then I went to work after taking a nap.

Then I went tout for work after taking a nap. Then I went to work after taking a nap.

I am a coach, and I havetaught three lessons today. I am a coach, and I taught three lessons today.

“have” sounds like you are taking the lessons. “taught”, “instructed”, or “coached” are better choices :)

I am a coach, and I haved three lessons today. I am a coach, and I had three lessons today.

We are still in the past tense for your story

The second class is for tiny tossddlers, so the parents would stay with their kids during the class. The second class is for tiny toddlers, so the parents stay with their kids during class.

“their” is a bit more natural.

The second class is/was for (tiny tossers?), so the parents would stay/stayed with their kids during the class. The second class is/was for (tiny tossers?), so the parents stay/stayed with their kids during the class.

This can remain in present tense (is, stay) because it is a current description of the class. However, I would still opt for "was, stayed" as continuation of the story I don't know what "tiny tossers" refers to, this calls for a brief description e.g, "... for tiny tossers, which describes XXX,"

There was a kid who used to do very well with his dad, but today he behaved bad todaly with a woman. There was a kid who used to do very well with his dad, but today he behaved badly with a woman.

There was a kid who used to do very well with his dad, but he behaved bad today with a woman.today he was with a woman and behaved badly. There was a kid who used to do very well with his dad, but today he was with a woman and behaved badly.

"behaved bad with a woman" implies that his behavior was towards the woman, rather than the woman accompanied him.

There was a kid who used to do very well with his dad, but he behaved badly today with a woman. There was a kid who used to do very well with his dad, but he behaved badly today with a woman.

There was a kid who used to do very well with his dad, but he behaved badly today with a woman. There was a kid who used to do very well with his dad, but he behaved badly today with a woman.

Then, she replied to me that she is his mom. Then she replied that she is his mom.

More natural: Then she replied that she was his mom.

What an embarrassing moment I had today. What an embarrassing moment.

Alternative: That was my embarrassing moment from today.

I am so sorry tofeel bad about mixing the kids up. I feel bad about mixing the kids up.

Using "I am so sorry" needs to be directed at someone, and here there is no one to direct it to except for us, the readers, which doesn't make sense.

Honestly, I am very bad at remembering their names. Honestly, I am very bad at remembering their names.

Honestly, I am very bad at remembering their names. Honestly, I am very bad at remembering their names.

Honestly, I am very bad at remembering their names. Honestly, I am very bad at remembering their names.