Welcome to the forum!
I don't have a Defender, but my journey started with looking for one. Now it's a 1982 Range Rover. From my experience, and I started with zero experience working on cars, stuff like prop shafts, lights and stuff turned out to be easy enough to fix in my drive way. Rust, especially on Defenders/90/110, is a different thing. I looked at a couple and would have tried fixing, or replacing, a frame. The body so is a different story. Also, paint jobs are the cheapest and easiest way to dress a car up.