I have some goals for 2023, and one of them is that I want to get 90a scores above 90 on the TOELF iBT test.

Sounds ackward when you say "to get 90 scores above"

Because I hope to go to France as an exchange student!M, my roommate recorded a video about our goals, and posted it on her instagram.

when you put a puncuation mark at the end of a phrase, you need to put a space between the comma and the start of the next word

Both of us are looking forward to an enriched life.

Before 2023, I didn't push myself so hard to improve my English.

need the space after the comma

On the contrary, I just stdudied whenever I wanted.

Although I feel kind of stressed and afraid that if I didwasn't be successful, what would my friends thoughtink of me,r. Revealing the goals in public is the best way to apply myself to accomplish it.

A run on sentence, split it into two sentences

Since my ability of writingwriting ability is poor, I challenged myself to keep a diary in English.

Wrong tense being used

This is the first day, and I will continue keeping it.

comma not necessary

I have some goals for 2023, and one of them is that I want to get 90o scores above 90 on the TOELF iBT test.

Both of us look forward to an enriched life.

I understand what you mean, but an 'enriched' life doesn't sound quite idiomatic. Perhaps you could say 'we look forward to having new experiences' or something

On the contrary,I just stdudied whenever I wanted.

Although I feel kind of stressed and afraid that if I didn't be successful what my friends thought of me,about what my friends would think of me if I'm not successful, revealing themy goals in public is the best way to apply myself to accomplish it.ing them (my goals)

Since my ability of writingwriting ability is poor,I challenge myself to keep a diary in English.

I have some goals for 2023, and one of them is that I want to get 90 scores above 90 on the TOELF iBT test.

A comment for the whole piece - best to include a space after commas and full stops.
On the test score - I think you mean score above 90, unless you want to pass the test 90 times? (That is what your sentence suggests)

Because I hope to go to France as an exchange student! My roommate recorded a video about our goals, and posted it on her instagram.

Include spaces

Before 2023, I didn't push myself so hard to improve my English.

On the contrary, I just stdudied whenever I wanted.

Although I feel kind of stressed and afraid that if I didI won't be successful and what my friends thoughtink of me, revealing the goals in public is the best way to apply myself to accomplish ithem.

Since my ability of writingwriting ability is poor, I challenge myself to keep a diary in English.

This is the first day, and I will continue to keeping it.

Minor suggestion - your original sentence works but this sounds more natural.