any thoughts on these hands appreciated

I'm trying to play ABC poker I've came to the understanding that you have 2 reasons to bet, correct me if I'm wrong:
-for betting for value is which is when you bet and think you can be called by worse
-for bluffing is trying to push someone off a hand better than yours

I have no info on villains
I open for 3bb and get called by BU and SB

flop gives me nut flush with 2 overs, SB checks and I wasn't sure if my bet is for value because I have no pair or flush
yet and I don't know if villain has hit the board so my hand would be called by worse if that makes sense. I knew my hand has pretty good chance at improving but I check and BU bets. I check raise him because I didn't want to call and miss on the turn being OOP and giving up initiative, what should I have been thinking about how to play my hand post flop here? after BU bet out
I thought he might have something so I just check-raised he folded and I think I may have missed out on profit by playing it that way.

$0.01/$0.02 No Limit Holdem
PokerStars
7 Players
Hand Conversion Powered by WeakTight Poker Hand History Converter

Stacks:
UTG ($2.47) 124bb
UTG+1 ($0.55) 28bb
MP Hero ($2.06) 103bb
CO ($3.33) 167bb
BTN ($1.88) 94bb
SB ($0.39) 20bb
BB ($4.07) 204bb

Pre-Flop: (0.03, 7 players) Hero is MP
2 folds, Hero raises to $0.06, 1 fold, BTN calls $0.06, SB calls $0.05, 1 fold
Flop: ($0.20, 3 players)

SB checks, Hero checks, BTN bets $0.10, SB folds, Hero raises to $0.28, BTN folds

Final Pot: $0.58

Hero wins $0.57 (net +$0.23)

SB collects $0.00 (net -$0.06)
BTN lost $0.16

HAND 2

2 people limped in I was SB I raised with KQs, Villain calls UTG. Flop comes I c-bet even though I missed, he calls.Turn comes I pair my Q but its a spade I check because again I'm not sure if I can get value or not he had called on the flop but because he limp called I don't know what range to put him on besides a weak pocket pair or some suited connectors 56s to JT's or weak Ax ( In the hand I was thinking mostly small pocket pairs trying to setmine) he bets 5bb on the turn which I thought was odd , maybe a small pair trying to make me fold If I had nothing since I checked which shows weakness. I called the turn the river comes and I was thinking he could have the flush , or a low pair . I didn't think a low pair would call me and a flush has me beat so I thought I'll check call if he bets I could have him beat sometimes.

$0.01/$0.02 No Limit Holdem
PokerStars
9 Players
Hand Conversion Powered by WeakTight Poker Hand History Converter

Stacks:
UTG ($1.57) 79bb
UTG+1 ($2.64) 132bb
MP1 ($3.75) 188bb
MP2 ($1.98) 99bb
MP3 ($2.08) 104bb
CO ($2.11) 106bb
BTN ($1.46) 73bb
SB Hero ($1.87) 94bb
BB ($3.37) 169bb

Pre-Flop: (0.03, 9 players) Hero is SB
1 fold, UTG+1 calls $0.02, 1 fold, MP2 calls $0.02, 3 folds, Hero raises to $0.10, 1 fold, UTG+1 calls $0.08, MP2 folds
Flop: ($0.24, 2 players)

Hero bets $0.18, UTG+1 calls $0.18

Turn: ($0.60, 2)
Hero checks, UTG+1 bets $0.10, Hero calls $0.10 River: ($0.80, 2)

Hero checks, UTG+1 bets $0.39, Hero calls $0.39

Final Pot: $1.58
UTG+1 shows a flush, Ace high


UTG+1 wins $1.52 (net +$0.75)

MP2 lost $0.02
Hero lost $0.77