Nl 20 Fold KK check raise Turn play ok?

A big NOPE.
To a min raise you should at least make one call and evaluate on the river.
Especially, cause it's a fish, they like these small reraises with no purpose.
- It could be a blockbet/protection with Q.
- It could be a fishy bluff with draw.

Usually they check the river, and if they bet big - you can fold.
Your call should also be quick, it usually scares bad players from bluffing again on the river It's just a theory, but I notice that quite often - some players tend to continue their bluffs, when they see you hesitating.

XunderdogX,

Preflop fine.

I don't think fold is that bad on turn, generally tun min-raises = the nuts at these limits. In practice I probably call turn and fold to a river barrel.