would I have to make the models & textures for everything myself or will they be provided? (I cant model or texture things)

I can do this one!  I'm an experienced dungeon designer, and can design caves, ruins etc. etc.   I'd like to claim this one, if that's okay:)

Can I recommend doing caves first? We got a more complete tile set and we might get new assets for egg mines. 

Okay.  What caves are there that I can do?

Frankly I wouldn't worry about them too much.  At the moment most assets are not completed.  Check cave claims section and navmesh add some rocks call it done for now.  We don't know what will be done with any of these interiors in the future.

Post a message saying you claim and post pics of work.  Make sure you have all the updated data and clean all your dirty edits.

http://tesrenewal.com/forums/caves-and-mines

Daedric shrines are also an option, but they may all be redone in the future and much clutter has yet to be modeled.