What are the mistakes that I have done in the following game? I am a begginer and I have a rating of about 1000 Elo. I played a game against stockfish 5 but I lost the game. I know that stockfish is a very strong engine but I played against it to learn more. This is the game:

[fen ""]
[Event "Computer chess game"]
[Site "Kartikay"]
[Date "2015.03.08"]
[Round "?"]
[White "Kumar Kartikay"]
[Black "Stockfish_14053109_x64_modern"]
[Result "0-1"]
[BlackElo "2200"]
[ECO "C01"]
[Opening "French"]
[Time "11:59:28"]
[Variation "Exchange, 1.e4 e6 2.d4 d5 3.exd5 exd5"]
[WhiteElo "880"]
[TimeControl "900"]
[Termination "normal"]
[PlyCount "44"]
[WhiteType "human"]
[BlackType "program"]

1. e4 e6 {(e6 Nc3 d5 d4 Bb4 exd5 exd5 Bd3 Nf6 a3 Bxc3+ bxc3 0-0 Ne2 Nc6 0-0
Re8 Bf4 h6 c4 g5 Be3 Qe7 Nc3 Be6) -0.26/21 21} 2. d4 d5 {(d5 Nc3 Bb4 exd5
exd5 Bd3 c5 dxc5 Nf6 Nf3 0-0 0-0 Bxc5 a3 Nc6 Bf4 Re8 Re1 Rxe1+ Qxe1 Ng4
Bg3) -0.17/21 8} 3. exd5 exd5 {(exd5 Nf3 Nf6 Bd3 Bd6 0-0 0-0 c3 Re8 Bg5
Nbd7 Nbd2 c6 Qb3 h6 Bxf6 Nxf6) -0.09/20 13} 4. Qe2+ Be7 {(Be7 Bg5 Nd7 Nc3
Ngf6 Qd2 h6 Bf4 Ne4 Nxe4 dxe4 0-0-0 Nf6 Kb1 0-0 Bc4 Nd5 Ne2 Be6 Bb3 c6 Rhe1
Nxf4 Nxf4) +0.34/22 12} 5. Bg5 Nd7 {(Nd7 Nc3 Ngf6 Qd2 h6 Bf4 0-0 Bd3 c5
Nge2 c4 Bf5 Nc5 Bxc8 Nce4 Nxe4 Nxe4 Qe3 Rxc8 0-0 Re8 f3 Nf6 c3 Bd6 Be5)
+0.31/22 18} 6. Bxe7 Nxe7 {(Nxe7 Nc3 0-0 0-0-0 Re8 Qd2 Nf6 Kb1 Nf5 h3 Ne4
Nxe4 dxe4 g4 Nd6 Qf4 b6 Ne2 a5 Bg2 Ba6 Nc3 Bb7 h4 f6 g5) +0.20/23 14} 7.
Nc3 O-O {(0-0 0-0-0 Re8 Qd2 Nf6 Bd3 Bf5 Kb1 Qd7 Nge2 Bxd3 Qxd3 Nf5 Rhe1 c6)
+0.26/23 8} 8. O-O-O Nf6 {(Nf6 Qd2 c6 Re1 b5 f3 Nf5 g4 Nd6 Kb1 a5 h4 Re8
Rxe8+ Qxe8 Bd3 b4 Na4 Ba6 Bxa6 Rxa6 Ne2 Ra8) +0.29/22 14} 9. Nf3 Re8 {(Re8
h3 c6 Qd2 Ne4 Nxe4 dxe4 Ne5 Nd5 Bc4 Be6 Kb1 a5 Bxd5 Qxd5 c4 Qd6 Qc2 a4 a3
f6 Ng4 b5 Ne3 bxc4 Nxc4) +0.51/21 16} 10. Qd2 Ne4 {(Ne4 Nxe4 dxe4 Ne5 Be6
Kb1 c6 Bc4 Nd5 Bxd5 cxd5 h3 a5 f3 a4 fxe4 f6 Ng4 Bxg4 hxg4 Rxe4 Rde1 Rxg4
c3 Re4) +0.39/22 24} 11. Nxe4 dxe4 {(dxe4 Ne5 Be6 Kb1 c6 Bc4 Nd5 Bxd5 cxd5
h3 a5 Rhe1 f6 Ng4 b5 f3 exf3 gxf3 Rc8 Rg1 b4 Rde1 Rc7 Qd3 Qe7 f4) +0.39/24
8} 12. Ne5 Be6 {(Be6 Kb1 c6 Bc4 Nd5 Bxd5 cxd5 h3 a5 Rhe1 Qd6 Ng4 b5 f3 Bxg4
hxg4 b4 fxe4 dxe4 Qe3 Rac8 d5) +0.41/22 19} 13. c3 Bxa2 {(Bxa2 Re1 Nd5 g3
c6 Qc2 f6 Nc4 b5 Ne3 Qa5 h4 Rad8 Nxd5 Bxd5 Bg2 f5 b4 Qa3+ Qb2 Qa4 Qc2 Qa6
Qb2 h6 Bh3 e3 Rhf1) +1.43/21 20} 14. Qe3 f6 {(f6 Bc4+ Bxc4 Nxc4 b5 Na5 Qd5
Qe2 Rab8 b4 Qe6 Qd2 Nd5 Rde1 Rb6 Kb2 e3 fxe3 Nxe3 h4 f5) +1.60/21 22} 15.
Nc4 b5 {(b5 Na5 Bd5 b4 a6 Kb2 Qd6 Qg3 Qd7 Be2 Bf7 Ra1 Nf5 Bg4 Nxg3 Bxd7
Nxh1 Bxe8 Rxe8 Rxh1 e3 fxe3 Rxe3) +1.85/21 26} 16. Nd2 Nd5 {(Nd5 Qh3 b4 c4
e3 fxe3 Nxe3 Bd3 g6 Qh4 Nxd1 Rxd1 f5 Qxd8 Rexd8 d5 a5 Nf3 a4 Nd4 a3 Re1 Re8
Rxe8+ Rxe8 bxa3 bxa3 Nb5 Bb3 Nxa3) +2.64/24 14} 17. Qg3 e3 {(e3 fxe3 Rxe3
Qf2 Qe7 Nf3 c5 dxc5 Qxc5 Qc2 Nxc3 Bd3 Ne2+ Bxe2 Qxc2+ Kxc2 Rxe2+ Rd2 Rc8+
Kd3 Bc4+ Kd4 Rd8+ Kc3 Rdxd2 Nxd2 Bd5 Ra1 Rxg2 h4) +2.94/23 36} 18. fxe3
Rxe3 {(Rxe3 Qf2 Qe7 Nf3 c5 dxc5 Qxc5 Rd3 b4 Rxe3 Nxe3 Bd3 Rd8 Nd4 Nd5 Qf5
g6 Qe6+ Kh8 Qf7 bxc3 Qg7+ Kxg7 Ne6+ Kf7 Nxc5 Nf4 Rd1 Rd5 g3 Nxd3+ Nxd3 Bb3)
+2.72/24 20} 19. Qf2 Qe7 {(Qe7 Nf3 c5 dxc5 Qxc5 h3 Rc8) +2.94/24 7} 20.
Bxb5 Rxc3+ {(Rxc3+ bxc3 Qa3+ Kc2 Qxc3+) +M3/120 0} 21. bxc3 Qa3+ {(Qa3+ Kc2
Qxc3+) +M2/120 0} 22. Kc2 Qxc3# {(Qxc3+) +M1/120 0} 0-1


So I want to learn from my mistakes so please tell me how can I improve my game.
The first mistake you made was playing against Stockfish. Modern engines are so strong (and have been ever since at least Fritz 5!) that you learn nothing from playing them. They'll punish all your tactical mistakes (and at 1000 Elo you make plenty), but you'd get much more useful tactics training out of just doing exercises. 

If you want to improve your game you should seek out human opponents somewhat above your level (100-200 Elo points) instead.