I can't figure out how to make all these parts move together. I joined them, however, they are still separate? How do I make my model move its parts together?
First: because you joined different objects that are now part of the same mesh, you have useless vertices. The fact that these vertices arent connected might create small gaps in your mesh during animation. I would suggest fixing this by either using 'remove doubles' or doing so manually in case remove doubles doesnt do the trick.
Second: weight painting should fix the problem.
1 of the many videos you can find on the subject: https://www.youtube.com/watch?v=5MJPq4k_aU4