Credit poinst are just "credit" in someones trade shop. You can exchange them for pokemon when you have them, and if you give them to others, then they can exchange them in your thread (provided you have one). Usually 1 credit = 1 pokemon.
A "BP" is a breeding project. Sometimes people might pay a few credits (or pokemon) to someone in exchange for the person RNG abusing the exact pokemon that they want for them. Simialarly, a "CP" is a catch projet. You would just catch the pokemon instead of breeding it.
Another one: "CMT" means Check my thread, used for trades to basically ask: What of mine do you want in exchange for this?
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