FA few weeks ago, I started a one-week training program.

If you’re discussing the past, then you need to use a past-tense of “start.”

In that week, I willas jogging one hour each day.

Past-tense

B, but there justwas a little problem about the location.

You can’t really start a sentence with “but.” You have to use a comma (although not always, but typically).

“Just” sounds funny in the sentence.

Not adding “the” before “location” sounds very wrong. “The” tells us that you’re referring to a specific place.

I neehad to take a bus to go to that sport center, which needstook 45 minutes to an hour.

Still past-tense. No need for “need” in that sentence. Although, you could say “I needed to take a bus” but “had” sounds more natural.

In total will beit took around 2 hours.

Past-tense.

This week I decided to jogging at my house.

“Jog at my house” or “to go jogging at my house.”

I was thinking I canthat I could save a biggreat deal of time.

Past-tense. Also “great deal of time” sounds more natural than “big deal of time.”

ButHowever, the truth iwasn’t what I was thinking at all.

Not sure what you mean by “the truth”… what truth? The “reality” perhaps?

BecausSince I doidn’t need to take the bus hence, I get up late., I woke up later than usual.

(1) Typically we never start a sentence with “because.” (2) add punctuation. Try to look up English punctuation rules! (3) you could say “I got up,” but it’s casual speak. “Woke up” is more specific. (4) The “usual” part adds more specification.

I spendt a longer time in eating breakfast, and shower…ing.

You could also say “taking a shower.” Also, you want to keep the flow of the words the same. If you start a sentence with “eating” and then you add more activities, make sure you end them with “-ing.” Example: “I ate and took a shower” is correct and so is “I was eat*ing* and tak*ing* a shower” or “She is cooking and crying at the same time.” Hope that makes sense.

In a realBy comparison, go toing to the sport center will beis more effective.

You could also say “going to the sports center would have been more effective.”

A calculateion mistake

FA few weeks ago, I started a one-week training program.

In thatFor one week I willas jogging one hour each day.

But there just a little problem about location.

Your sentence is good! You can also say "But the location was not ideal"; or "But the location was a little problematic."

I neehad to takecatch a bus go to thate sports center, which needtakes 45 minutes to an hour.

In total will bit would take around 2 hours.

This week I decided to jogging at my house.

I was thinking I can save a biggood deal of time.

But the truth isn’t what I was thinking at all.

Or, "But the reality wasn't what I expected."

Because I don’'t needhave to take the bus hence, I get up late.

I spend a longer time in eating breakfast, showering…

In a real comparison gity, going to tohe sports center willould have been more effective.