Illustrator not working as expected

I'm learning to use Illustrator for a college class and am having a lot of trouble with it.

It keeps randomly crashing, the "bring forward"/"send backwards" options aren't working, and the gradient tool only works for some things, but not all. I'm sure there are other things I haven't found yet that don't work.

The crashing only seems to happen when I'm not directly on it; like I'm on chrome or Word, but still have it open.

The forward/backward don't work but the "send to Back" and "Bring to front" work.

The gradients I'm trying to do are radial and they don't show up on most things. I'm trying to do them colored through a tutorial with pictures of the menus and how it should look, but after putting the information in mine don't look anything like their design because the gradients don't do anything. "Inner glow" works, though.

Sorry, I'm just frustrated with this and worried about my grade. If anyone has any hints, I'd love to hear them!

Thank you!