What can I learn from this loss?

I know I left two different pieces hanging loss them because of that. What else does it seem that I need to work on? (Also I don't know how to post games the way everyone does where it's like a little window. Someone explain that to me and also do it for me this last time?). Thank you! [Site "Chess.com iPhone"]
[Date "04/07/2017 05:11PM"]
[White "Therealfisher (1292)"]
[Black "Justinming (1296)"]

1.e4 e5 2.Nf3 Nc6 3.d3 Bc5 4.Qe2 d6 5.Be3 Bb6 6.Nc3 Bg4 7.O-O-O Qf6 8.h3 Bh5 9.g4 Bg6 10.Qd2 Qxf3 11.Rh2 Qf6 12.d4 O-O-O 13.g5 Qe6 14.d5 Bxe3 15.fxe3 Qd7 16.dxc6 Qxc6 17.Nd5 h6 18.gxh6 Rxh6 19.Kb1 Bxe4 20.Bd3 Bxd5 21.Bf5 Be6 22.Rf2 g6 23.Bxe6 fxe6 24.Rdf1 Rxh3 25.b3 Qd5 26.Qc1 Ne7 27.e4 Qxe4 28.Qg5 Qh4 29.Qxe7 Qxe7 30.Rf7 Qh4 31.Rd7 Rxd7 32.Rf8 Rd8 33.Rf1 Rh1 34.Rc1 Rxc1 35.Kxc1 Qf2 36.Kb2 Rf8 37.Ka3 Qd4 38.b4 a5 39.c3 Qxc3 40.Ka4 Qxb4# {Black Wins}

i dont think we can post a game directly from app

we might be able to go onto website, via safari, and link it from there

First, you hung a knight in the opening, which was the main thing, on move 10.

 

In chess, you should realize that move quality is based on your opponent's ability to respond to those moves. 

This means that even if you think you played something well, if your opponent can do something really horrible to you (like win a knight), then it turns out, your move isn't that good. 

 

So before each move, you should carefully ask yourself - "If I make this move, can my opponent immediately just win something?" 

 

You should also study tactics to make this more effective.

A good book for your improvement (in fact, the best book, I'd say), is Dan Heisman's Back to Basics: Tactics. Reading that book, and applying exactly what it tells you to do in your own games is the best way for you to improve, at your level. 

You can learn by Not Hanging pieces again .

Thank you everyone!