Welcome to Linuxquestions.
There are a few things to note when asking questions, an informative and specific title will help people respond to your problem, "need hlep!" doesn't really do much for people, please is also a nice addition to any post
Now the problem at hand, the different versions (or types as you put it) are called distributions (distros for short), these are collections of the base Linux system (Kernel, system programs) and other packages etc. the distribution vendor has added in. The Base is the same in pretty much all Linux distros but things like paackage managers (how to install programs) and admin tools can vary greatly.
If you search these forums you will see hundreds of the same types of posts, yes it is hard and confusing when starting out, but a little reading will go along way, you need to work out your requirements, as in what you need the system to do, what hardware you have, technical ability of those using the system. Once you have answered those questions and any others you have, you can begin looking into distros, my sig has a link to an intuitive system for picking the distro for you. The best pat, if you don't like one you can get rid and try another for free. There are loads listed here; http://distrowatch.com/
Do be prepared for some reading and work, but it is most definatly worth it