20/40 (10% $5max. rake no rake if no turn) @ Trump 8-handed.
One just left. The player on my left is waiting to post as is another player who was just moved. Semi-tight for a Thursday night (which have been active lately with school out) table with a lot of limping PF as opposed to PF raising. The player in the CO was fairly aggressive on many streets, but not all that loose. His cards were at least mathematically justified as far as I could remember through the session. I wasn't really paying much attention to MP2, in all honesty, so I had no read there. He was a frat lookin' kid with sunglasses and a Duke hat, if that means anything to you.
Me:

in the BB
PF:
3 folds. MP2 calls. CO calls. Button and SB fold. I check.
Flop (pot= $70):

(might've been a diamond)
I bet. MP2 calls. CO raises. I ________?
I'm not gonna fold, but am I raising or calling and what am I looking to do with the wide amount of cards that can hit the turn when those cards hit. If a blank hits, the board pairs, a spade hits, a 9 hits? What about a Queen, King, or Ace? What's your gameplan in this spot?
And question #2 can be seen here:
JTs in the BB Pt. II