Villain is 21/15, seems pretty solid over 100 hands or so.
Preflop, I 3bet because I've been 3betting a lot, this time for value because I think I can get worse aces to call etc.

On the flop I see his minibet and take it as weakness somehow, maybe he hit a pair or is on a flush draw so I raise. Is the raise a good size? How much should I raise to?

On the turn he does a tiny bet again and not sure what to think of it.

PokerStars - $0.16 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

BB: $15.48
UTG: $18.26
MP: $19.43
CO: $9.57
Hero (BTN): $16.23
SB: $18.02

SB posts SB $0.08, BB posts BB $0.16

Pre Flop: (pot: $0.24) Hero has A J

fold, MP raises to $0.48, fold, Hero raises to $1.92, fold, fold, MP calls $1.44

Flop: ($4.08, 2 players) 4 J 7
MP bets $1.12, Hero raises to $4.00, MP calls $2.88

Turn: ($12.08, 2 players) K
MP bets $2.40 Hero =???