[Nightwish]

Preflop is fine. Given that you have no info on the opponents, I agree with Barron that calling is better than 3-betting.

On this kind of flop, I would typically go for a check-raise. Essentially, it all depends on the PFR's position. Given that the PFR is third to act (out of four), I expect the action behind me to go check, bet, call, so then my check-raise would hopefully get BB to fold and extract value out of the other two. Had the PFR been last to act, the check-raise would be even more correct because most players would check to the PFR, so my check-raise would then clear out the field. Had the PFR been in the BB, betting the flop would have been the best course of action because you then want the PFR's raise to clear out the field.

As it stands, the BB made a surprising bet, everyone called, so now you must check-raise to extract value. After that, I would bet the turn.