Bluffing is by far my biggest leak lately, but I really want to learn to get better at it, so any comments are appreciated.

I have been pretty much abc tag, and have not played more than a smallish pot yet after around 60 hands.

Villain is loose-passive, so I know - bad target for bluffs...but I read him for a weak hand based on his limp and quick calls. He played a big pot once so far, where he made a str8 flush and min check raised and eventually stacked ace high flush.

What do you think?

Poker Room skin
No Limit Holdem Ring game
Blinds: $1/$2
5 players
Converter

Stack sizes:
UTG: $440
CO: $224.20
Button: $200
SB: $560.70
hero: $204.80

Pre-flop: (5 players) hero is BB with A 6
3 folds, SB calls, hero raises to $7, SB calls.

Flop: 3 J K ($14, 2 players)
SB checks, hero bets $9, SB calls.

Turn: 8 ($32, 2 players)
SB checks, hero bets $20, SB calls.

River: 5 ($72, 2 players)
SB checks, hero bets $50