What do you think of this layout for a online learning system?

Hello Flutherites!

I made a new layout for my online learning system, but I am a bit in doubt about it. I don’t know if it’s a good layout for a learning system, but I also don’t know (and don’t know how to) design a good one for the purpose.

If some could rate my layout, and give some pros and cons, I would be delighted.

The link is http://ole2.daveyyzermans.nl/ and please also look at the login page.

Thanks in advance!
Davey.