Books! Some reloading manuals are in order. I'd suggest Lyman 49th edition Handbook, ABCs of Reloading, Modern Reloading by R. Lee. These will get you informed enough to set up your first reloading system. When you're up and running I'd add one or two manuals from bullet manufacturers, one or two manuals from powder manufacturers, and a "neutral" like Lyman's or Lee's. And of course read the stickies.
I agree with starting with a single stage press. You will learn the "why" (theory) of each step, and changing/adjusting dies will show how die adjustments effect the finished round.
Reloading is a very rewarding part of our hobby and besides, it's fun
Go slow, be safe, and enjoy!