TPMK lead into on turn after monotone flop

Villain completely unknown.

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

BB ($92)
UTG ($79.80)
MP ($50.75)
Hero (CO) ($50)
Button ($62.30)
SB ($49.60)

Preflop: Hero is CO with A, J
UTG calls $0.50, 1 fold, Hero bets $2.50, 2 folds, BB calls $2, 1 fold

Flop: ($5.75) A, 4, 7 (2 players)
BB checks, Hero bets $4.50, BB calls $4.50

Turn: ($14.75) 10 (2 players)
BB bets $12, hero ?

Against a complete unknown, I'll call and reevaluate a river planning to call most. I usually have at least a loose/tight read though to go off of.

I would definitely not raise, Id say this is 65% toward someone trying to get 3 streets of value where he thinks you might check behind on turn and 35% random bluff from villain. Either case call and see what he does on the river. Reads are really nice though in these spots. Against some villains I'd muck right there; other fish you can raise here because they are just taking random stabs and don't fold. But calling is the play vs. unknown.

I think I call turn and fold river because we're essentially bluff-catching and I'm not giving an unknown credit for a multiple street bluff.

Unfortunately this one of my first hands at the table. I agree having even a slight idea of villain being loose/tight helps making the decision.

I folded turn already, because;
- Villains betsizing is weighted towards value
- Better A's/2 pair/sets are possible
- I definately have to fold to any spade river aggression, maybe to any river aggression
- If villain is really bluffing I think he has to bluff the river a large % of time. That might be too much credit for an unknown 50NL villain though, and it's an argument for calling 2 streets with our hand.
- All my 'outs' are tainted

On the other hand, worse Ax is a possibility and so are random bluffs.

This is almost always like AQ/AJ/AT w/ no spade. It's super transparent, I'd say villain probably has AT super often. I'd call and bluff spade rivers.