flop top two pair from BB

[VirgilStarkwell]

This is my first post to this forum. I've been playing online micro limit and live small-stakes limit for a while. Unfortunately, the big limit game around here is 5-10, so I am hoping to learn no limit. I probably shouldn't be anywhere near a no limit table except everyone here plays so badly.

I'm posting two hands from a 1-2 $100max session last night. My table image was weak-tight and inexperienced. Here is the first hand.

I am BB in seat 9 and I have $180.
Seat 10 is an older taggy gentleman with $60.
Seat 4 is the big stack with about $300, plays slag and running good.

5 or 6 players limp and I check with Ad4d.

Pot=about $8 after rake.
Flop is A34 rainbow.
I bet $10, seat 10 calls, seat 4 raises to $20.
I call and seat 10 calls.

Pot = $68
Turn is 3, we check to seat 4 who bets $20. I minraise to $40, seat 10 folds, seat 4 calls.

Pot = $148
River is 9, no possible flush. I check, seat 4 bets $30, I should...?