The purpose of the projects is to test whether you have understood everything in the course. If you just copy someone else’s code the certification becomes meaningless.
If you have taken the course and have trouble doing the projects, you can retake the course or look for other resources like the documentation on reactjs.org (which is rumoured to be very good), video tutorials or another online course. I can’t help you more than this, because I have just started the react course.
Addendum: I am going to look for another React course, because I am not going to learn it with this one.