Well for starter's i'd check out the crafting/gather forums for a guide, there bound to have a couple, you might also check youtube.

That said, the *, **, ***, **** are referred to as "stars" and those are the elite crafts for max lvl crafters (with the best gear available) it will take you either a lot of time or a lot of gil (most likely both!) to get to those.
The CP is "crafting points" you always have a full bar before a craft so you don't have to wait to craft stuff which is nice, you'll get more of these as you get better gear, it's also worth noting these are super important if you want 100% hq on your crafts!
GP is gather points, and its for gatherers not crafters so dont worry about that yet!