Actually CP stands for Combine Points. Combine Points is a reward system that gains you in-character (IC) items for out-of-character (OOC) actions.
There are multiple ways to earn CP's.
1. Clicking on banners. Each banner you click on will earn you 10 CP's. Head over to the Combine Points page and start clicking banners to earn some.
2. Create a Star Wars related site. If you create a fan site, you can submit it to the banner rotation system and earn some really good points that way.
3. Combine Rewards Page. Make a purchase through one of the Combines affiliates and you can earn the big bucks! This method requires the most on the side of the user, as you have to usually purchase something or commit to a free trial. Most of the offers you have to at least enter a credit card number to receive them.
4. Help the community. If you find a typo, a missing image or a creature/item/ship whatever is missing a description, make one up for it and submit it!