>>48564221Late reply but.
If you are lower level than 30, prioritize high CP mons, but don't power them up. Keep 3 Stars and check
https://gamepress.gg/pokemongo/attackers-tier-list for good Pokemon for good raid Pokemon.
Generally, for raids you want max attack.
If you have ANY interest in PvP for Great League and Ultra League, you'll have to use external resources to figure out which stats are good for PvP. If you want more information on that I'll help you out.