HiRez made Paladins P2W again. If I have to pay for a game, might as well play Overwatch. What should a beginner know?

I'm aware of general differences between Paladins and Overwatch (like OW having bigger maps, faster rate of ult generation, more powerful ults, no passive health regen, no items or loadouts but you can switch characters to adjust to the enemy comp) and I'm not unfamiliar with team-based shooters, so I know shit like "we have no tank or healer, better not play another DPS".

I'm looking for tips on things like what's meta, character abilities that might surprise me, are there tank characters that actually aren't good solo tanks, are certain healers better pocket healers than team healers? That kind of stuff.