I just figured out that I can't skin, code, and mesh not just because I don't know how to, but because I CAN'T at all. I don't have WinRAR, the only program I know of that can open those Zoo Tycoon 2 files.
Great. It's a really huge setback, if not a pernament obstacle that will completely keep me from joining the Zoo Tycoon community. That just leaves me as a researcher/dreamer that can't modify ANYTHING from Zoo Tycoon 2.