Game against FM Shawnrl

I don't think I made too many blunders, where could I improve?

Why 9 c4? You give Bg7 scope and purpose. 9 c3 to restrain the black Bg7 looks more solid.
Why did not you take the free pawn 13 Rxe7 or 14 Rxe7?
Why 16 Qe2 and 17 Qc2? You could play 16 Qc2 directly.
Why 17 Qc2 and not 16 Rad1 to protect d4 and to remove your rook from the diagonal of Bg7?
Why 18 Ree1 and not Rae1? Otherwise 14 Re5 was meaningless.
Why 20 Qb2? If that is where the queen must be, you could have played 17 Qb2.

thanks for the input, I hadn't even realized I made these errors

Your whole play seems lacking a plan: Re1-e5-e1, Qe2-c2-b2-c3-e3-e4?, Ra1-d1-d2?. Maybe as an 1 d4 player you are not familiar with the Caro-Kann Defence?

Around move 44 you clearly have no idea what to do. You're just pushing your pawns aimlessly, better is to think that the goal is to promote so you need to get rid of the rook from behind your pawn with kf1 and ke2

Around move 44 the game was lost and time was nearly up.

I guess don't line up your queen and rook when there's a bishop that can attack that diagonal. I'm talking about move 23

6.Nxf6+ is amazingly drawish.

After 6 Ng3 "the knight is not particularly well placed"
Karpov won some fine games with 6 Nxf6+ and 7 Ne5. As he played this also with black, he was the authority on this variation.
5 Nf3 still looks more natural than 5 Bd3 or 5 Ng5.

Appreciate the advice all of you. :)