AtIn Today’s English Class

I had to write an English essay on the topic of finding frombased on an article in an English class.

The source/topic for your essay was the article, so I changed the wording to "based on an article"

However, I could not writefinish it by the end of the time limit, so I was disappointed and nervous because my classmates around me wasere able to write easily.

"I couldn't write it" means you didn't write anything
"Were" instead of "was" because the subject (classmates) is plural

Although I studyied hard to remember vocabulary, it was yen't practical/applicable yet, so I’ll study more.

I think "applicable" is a more fitting alternative as an adjective in this case, but practical is fine

At(In) Today’s English Class

We typically say "in class." However, for a title, usually you would leave off "in" entirely

I had to write an English essay on the topic of finding from an article in anmy English class.

However, I could not write it bywithin the time limit so. I was disappointed and nervous because my classmates around me wasere able to write easily.

Inside the range/border/limit of something => within

Although I study hard to remember vocabulary, it was not yet practical, so I’ll study more.