Turned a wheel, but I'm still scared for some reason

[TheSalche]

100 NL on Pacific, villain is new to the table. Hero is in the BB with 55, with 6 total seeing an unraised flop of ...

2 3 4 rainbow (~$6 in pot)

It gets checked around to LP who bets $2, Hero calls, and Villain calls.

Turn: Ace
Hero checks, gets checked around (LP checked quickly)

River: 7 (~$10)
Hero bets $7, Villain min-raises, LP folds, Hero calls

Should I be betting this turn? Did I play this scared (worried about 56)? Should I 3-bet the river and fold to a raise?