Preflop: I iso here so that BB won't get to see a free flop and because we take initiative + sometimes these retards even fold.
Flop: I lead yeah pretty standard.
Turn: In a way it's close but then again it's not really so close, I never check/call, why? We give straight draws free chance to check back, we miss value from worse 9s because they might also check back realising that value betting weak 9 into 2 opponents is probably going to be suicide.
River: You have to decide whether they had draws or made hands, their flop and turn range is like JT T7s T9 J9 Q9 A9 maybe 89 but rarely because in general we see more turn action, but then again because you checked you make it so much harder to hand read, if you bet turn and he doesn't raise, you can assume you atleast have the best hand a good % of the time.
On this river, as played I also just bet, it's much less likely they will bluff missed draws into 2 opponents and they are capable of levelling into calling worse because they are spewtards and the 9 makes it less likely you have one.
I think the key here is 1) not to play scared and 2) realise why you are doing what you are doing.
If you raise pre, you isolate often and we don't have this awkward multi-way, you should realise that you are also value raising here, K9 is probably good vs his range and we take initiative, + get in a bigger pot with quite clearly a weaker player who will probably quite often fold to a cbet, resulting in a really profitable spot.
You can then go ahead and just bet flop & turn for value, for sure it's thin and sometimes you are beat, but in general when player flats turn they don't have you beat (apart from A9) because players will most likely raise turn with 2pair+.
On the river you can then quite clearly say to yourself "I have the best hand here super often, should I check to induce a bluff or just straight up vbet". I mean let's think, the draws missed (apart from backdoor spades), so hes going to likely call you lighter, you need to judge your opponents aggression and realise whether or not he will bet his busted draws on this brick, I think personally vs unknown I make a value bet that I think 8x would level himself into.
Hey maybe my advice sucks

I'd be interested to read the hand judges thoughts.