Just getting back into poker and feel I'm a little rusty hoping I could get some opinions on this hand, thanks in advance.

I had just sat down, this was my second hand at the table and don't have stats.
Think pre is pretty standard, always looking to play suited connectors multi-way and I know there are at least two others going to flop.

Poker Stars $0.10/$0.25 No Limit Hold'em - 6 players -

BTN: $19.65
Hero (SB): $25.00
BB: $25.00
UTG: $48.34
MP: $25.97
CO: $47.75

Pre Flop: ($0.35) Hero is SB with Qd Jd
1 fold, MP raises to $0.75, CO calls $0.75, 1 fold, Hero calls $0.65, BB calls $0.50

Flop: ($3.00) Kd Jh 9c (4 players)
Hero checks, BB checks, MP checks, CO bets $1.90, Hero calls $1.90, BB folds, MP folds

So obviously fairly coordinated board, calling ranges pre are huge at this level so when CO bets I'm thinking he's either stabbing at the pot or betting out with, Kx, 10x, Qx, Jx, 810, 78s or he could have flopped the nuts with Q10. KK JJ 99 KJ are all out, as I think he 3-bets them preflop.

Turn: ($6.80) Jc (2 players)
Hero checks, CO bets $3.24, Hero calls $3.24

At this point I think I'm most likely ahead and didn't see much reason to lead as it probably causes worse to fold and eliminates all of his bluffs.

River: ($13.28) 6s (2 players)
Hero checks, CO bets $8.45, Hero calls $8.45

Same reasoning as turn for play here. I think he check backs most of his Kings here. Really wasn't sure if I should be raising or folding with that sizing and aggro throughout hand. Sort of felt like a weaker J at this point, a straight, or air.

Thoughts?