>>48229791Depends what you want your mon to do. CP only really matters when it comes to ensuring a mon can be used a specific pvp tier, but CP is decided by a combination of levels and IV (the stars) Certain mons are best for PVP when they have uneven IVs (stars) but when it comes to PVE, you want the IVs to be as high as possible when choosing what Pokémon to level up. So, both things are equally important.
If it seems too complicated to start with, just ignore PVP for now, focus on PVE (raids and rocket battles) and try to get mons with perfect 3 stars or above and who have high cps. Save your stardust for hundos/perfects though.