My English skills are to bad to understand everything. But i know i can do it!
Just use FCC as a chance to work on your English skills. There are a lot of non-English speaking jobs out there, but even having a basic level of English will greatly improve your opportunities.
And the forum is a friendly and patient bunch - don’t worry about it.
It’s also good advice to practice every subskill of a language:
Using a forum is mostly Reading and Writing, so it makes sense to also practice the Listening and Speaking part.
Feedback is also very important.