Generally, I read them which, ones I wrote ion the same date andy in a different year.

If there weare pictures oin the old journals, it is betteasier to remember.

For example, iI read journals ofrom Nov 5th 2020, 2019 and 2018.

As I went maple-viewing two years ago, and because of my old diary entries, I am able to make a plan that I will go go to parks to see maple leaves this weekend.

5Five years ago, my first son started to speak sentences.

Generally, you should spell out numbers that are less than 10. :)

I totally recommend to writeing journals like this way.

After you are able to seead your old journals, you will know the joys of writing journalsthem.

Or, you could also say: After you view your old journals, you will know the joys of writing them.

Generally, I read them which,those I wrote ion same date and different yeary a year ago.

which is used to ask for *specific* information (for example, "which park did you go to yesterday? Did you go to the national park or the X name park?", "which movie would you like to see? (out of all of the movies we can watch right now)"). it's used when you have more than two options, and the speaker knows what they are.
It also can be used in situations like "The book, which I wrote" but sounds a bit literary :)

If there weare pictures on the old journals, it is betterhelps to remember them.

"it is better to..." here has the connotation of advice? of something you should do? like "it is better to not forget what we saw" "it is better to study for our exams" etc
Here I found a much more clear definition: "used to give your opinion or make a suggestion about what you think should be done or happen"

For example, i read the journals ofrom Nov 5th 2020, 2019 and 2018.

from instead of "of" because the journals are *from* those years. ex: I read all of the newspapers from 1997 to 2000.

As I went maple-viewing two years ago, I am able to make a plan that I will goJust like I went to see the maple trees two years ago, I'm planning on visiting the parks to see the maple leaves this weekend.

few changes here:
"I'm" instead of I am because it sound more casual. You're always going to use this casual form, unless you're on a really formal situation or you want to distance yourself from the person you're talking to.
I deleted "I am able to~" to "I'm planning on visiting..." because it sounds more natural. "I am able to" it sounds like something didn't *allow* you to go to see the maple trees. I'd suggest using "can" instead of "able to" if you wanna sound more natural :) "Just like I went to see the maple trees two years ago, I can plan on visiting..."

5 years ago, my first son started to speak sentencehis first words.

I totally recommend to write journals like this wakeeping a diary.

Few changes here, too!
"like this way" sounds natural in korean, but in english it's used only on very precise situations. Like "did he go this way or that way?", "why did you do it this way, I told you to do it my way"
I'd also suggest writing "keeping a diary"! There is a slight difference between the two, actually. A diary is used to record events, while a journal is used to reflect on things :) and keeping a diary here would mean the activity of writing kn one.

AfterWhen you are able to see old journals, you will knowad your old entries, you'll discover the joy of writing journals/keeping a diary.

Here it sounds a bit awkward to me, but I can't actually pinpoint the reason why :/ Sorry!