1) A mp7 seems overly ambitious. I would start out smaller, go for a knife or a simple tool. It is much less likely to end in frustration. It will also lay the ground work and workfllows for modeling a mp7, later. https://www.youtube.com/watch?v=Z9wgKy-F1Rw https://www.youtube.com/watch?v=pC9MdCg1k1A 2) You don't need to…
Once you've run through a couple tutorials and you can confidently make most shapes and observe good modeling practices, the rest is easy. Google MP7 parts, and there you go. Great thing about modeling guns, you don't have to make anything up. You could even look up exact dimensions of parts if you are into replication.