Do you need to bother with a 2 stage paint? That's up to you! It depends on what you want as a finished product. BC/CC will last longer. It is also easier to spray if you are new to painting, as mistakes can be repaired as you go along. If you get a run in the base, you fix it before clear. After the base is the way you want it, you shoot the clear. If there is a problem with the clear, you can fix that, and shoot more clear on it.
My understanding is that you can sand and buff single stage if it is not a metalic color. Since I use very little single stage, I can't say that for sure, but that is my belief.