CO is 33/6 loose passive pf, weak/tight postflop. BU is 32/28 LAG, aggro postflop. 100% CB. I am a 24/20. We have no real history. Should I be 3betting in this spot or calling to keep in the fishy player? It seems like there's little value in 3betting this. Is there more value in calling in these spots?

Poker Stars $0.50/$1.00 No Limit Hold'em - 6 players
The Official DeucesCracked.com Hand History Converter

BB: $209.80
UTG: $112.75
MP: $106.15
CO: $81.70
BTN: $151.75
Hero (SB): $149.65

Pre Flop: ($1.50) Hero is SB with K J
2 folds, CO calls $1, BTN raises to $4.50, Hero ???

Thanks. I've usually 3bet here, but I think I'm mixing up some concepts. I've heard a lot of ppl advocating flatting stronger hands that are usually dominated if they're called, and the 3bet is really never called by worse. So villains will fold worse or call better, and 3betting will fold out the hands that are dominated by you. On the other hand, I hate calling and basically being forced to make a hand, short of running a c/r bluff on a safe flop.

Does 3betting the KJ against a better LAG (not one calling 3bets often, no history so little chance of him calling/4bet bluffing)just turn it into a bluff? Is it going to be better to just win the pot/take the initiative in this spot? What type of villain would you flat KJo with if any? Finally, whats the worst hand you might just flat-call in this spot, if any (KQ?)

I'm really trying to improve this part of my game. You guys are awesome.

and the 3bet is really never called by worse.

like i said, if i cant coldcall profitably, i may 3bet as a bluff or for value. now that i cant coldcall oop there are more hands to 3bet as a bluff. i think what needs to be discussed is which hands are best to turn into a bluff against a specific player.
tbh i never thought about when(against whom) its best to 3betbluff suited conns OR KJo oop.

thoughts?

need to add, that the sb is kind of special, because theres still BB behind. in the BB you are able to coldcall a bit more (without a limper)