So, the bests did 1min30 seconds to finish the tour and I did 1min 41 / fastest runner finished in 1minute and 30 seconds, and I finished in 1minute and 41 seconds.

This is the only sentence that was not corrected, so it's the only one I'm correcting. "Tour" is definitely French and not used in English in the context of running a short, timed race or sprint. I'm not sure exactly what you ran, which is why I'm not suggesting an English word to replace "tour."

The French professor often gives bad grades so the last test we did, I got 12,5 and it was the best grade of the class.

I tryam trying to gain muscle so I have to eat a lot of protein and I know thery're both are great for that.

Afterwards, I went to the school.

"school", "work" and "university" are a little unusual in that you can "go to school" in general without specifying which school. It's generally more natural to say this as well.

During the commute, I learned some words in English.

For example, today I learned the expression "to have a blast" orand the verb "to board".

At first, I had class of Spanish class.

The courselass was pretty good.

I made some good interventions (?), and as I learned my lessons, I was able to answer to some professor's questions.

Not quite sure what you mean by "interventions" here.

The second courselass was a courselass of English.

"class" vs "course" is a little tricky, but "course" would be like your assigned study material for the semester/term, while "class" would be one period of learning it.

My professor gave us back the (different) tests we did last week.

I think you can omit different and it will sound more natural

I was really surprised to get the grade of 5 out of 20 in the oral comprehension test because basically, I always have great grades.

Nevertheless, I got thea grades of 20 in both written comprehension and written expression.

It's reallly strange to have 20 and 5 in the same subject, but the professor is weird too, so I think ithat's the main reason.

After the English class, I had the sport classPE.

"sport class" is more naturally referred to as PE (which is an abbreviation of physical education)

We had to predict our times for running 500 metters distance.

I'm not really good inat running because I don't like it.

So, the bests did 1 minute 30 seconds to finish the tour and I did 1 minute 41.

If you want a really concise way to write this, you can use "1m30s", but we usually don't abbreviate minute and then not abbreviate seconds also.

However, I was happy because I well predicted my times well so I think the grade will be pretty nice.

It was about the death condamnationpenalty.

I'm not sure I succepassed it but I did my bestter and I think ithat's the most important.

The French professor often give bad grades so in the last test we did, I got 12,.5 and it was the best grade of the class.

In English we use the "." (period/full stop/dot) as the decimal seperator.

The class' average was about 9.

"class" can also be an adjective, and is more naturally used here as an adjective than as a possessive noun.