1... Nc6 is horrible for your opponent. It blocks the c-pawn and disconnects the Knights.
5... Bd6 isn't totally weak, but the Bishop serves no purpose there, since the diagonal it usually attacks is fortified by White's pawns. The most common reply is 5... Be7, which neutralizes the threat of Bg5 and keeps extra protection for the pawn on d5.
6 c3 is silly, in my opinion. More to the point is the direct 6 c4 or even the direct 6 Bg5.
7 b4 is premature. You need to get your pieces developed before you launch a Queenside pawn attack. Fortunately, Black panicked at the sight of your pawns and wasted a move. Black should go about business with such as 7 ... Re8.
9... b5 is horrible. It's probably the worst move Black could make that didn't give away material. He walks right into your plan and accelerates it. I guess Black panicked at the pawns. There was nothing to worry about, as they have no pieces to support them. Black should go about his business with 9... Re8 or even the direct 9... e4.
10 axb5 axb5, 11 Bg5 is more accurate. Then Black has to waste a move protecting the pawn on b5. With your move, he can escape that problem with 10... bxa4. Instead, Black's 10... h6 is another waste of time. Almost any other move would be better.
11 axb5 axb5 (11... hxg5, 12 bxc6 Bxc6, 13 Nxg5 is good for White) is a little more accurate, and now 12 Bxf6 Qxf6, 13 Nxb5. Black has some counterplay for the pawn, but you've accomplished your goal.
12 ... Ne7 is a bit better than Black's move. Since a pawn has to be lost anyway, Black gets more space to move in. After 13 bxa6 Rxa6, followed in some lines by ... Ba4, Black has a bit more counterplay than in the game.
13... e4 is a horrible move for Black. Almost everything else was better.
15 Nxd6 is a blunder. After 15... exf3, 16 Bxf3 Qxd6, you're down a piece for two pawns. Of course, Black fails to see even that simple combination.
Moves 16-18 are probably best for both sides.
19 Rd1 would be a good choice, threatening Nxe4
20... f5 is a bit better for Black, as it makes it harder for you to hold onto your pawn advantage.
22 Rd1 is still a good choice. You need to get the Rook into the game.
24 Nxe6? of course is an error. 24 Bd3 or Bf3 holds onto everything.
24... Nxe2+ is a bit more accurate for Black.
62... Rg8 is not the losing move.
64... Ke7 is the losing move. Black can drive you away with Rook checks or even play 64... Kg7, tucking the King into h6 later.
66 Kg6 is direct and effective.
66... Re8+ puts up a fight, cutting off your King from the pawns. After 67 Kf6 Re6, Black has counterplay and may be able to draw. You'd need to play 67 Kd5 Re3, 68 Rxg6 Ke7, 69 Rh6 Rxg3, 70 Ke5
80 Rg7+?? gives the win away. 80 f6 is straight to the point and wins easily.
86 ... Ke8?? gives the win right back. All Black needs to do in this position is shuttle the King back and forth from f7 to f8 and get the Opposition whenever your King moves to the sixth rank. If you then push the pawn, Black moves in front of it, and you must either lose the pawn or stalemate Black. 86... Kf8 draws here, i.e. 87 Ke6 (K-any Kf7) Ke8, 88 f7+ (88 K-any Kf7) Kf8, 89 Kf6 stalemate.
88 Kf5?? gives the win away again. After 88 f7 Kg7, 89 Ke7, the pawn promotes.
89 ...Kg8?? gives the win back (89... Kf8 draws)
90-92 You finally got the right idea and pushed the pawn.
this was an interesting 10 minute blitz game I played here on chess.com. I played king's indian attack and transposed into a reversed classical pirc setup which I know quite well. I got a slight advantage in the opening so I started trading down the pieces in the middle game, but I played inaccurately and ended up playing a drawish endgame. my opponent didn't accept the draw because he had 4 minutes more on his clock. but then he chose the wrong plan and handed the game to me.
let me know what could I have done better. but please don't say stuff like "bad opening!", because I know my openings and like to play the positions that arise from them.