What should I have done
Check out this #chess game: HeineKas vs Pyfonian - https://chess.com/live/game/44790603599 Here is the game link
You let white get a massive center and traded the only piece you developed. You totally neglected piece development and king safety. After 10 moves, you have no pieces developed at all.
Once a few things traded, your poor king was hit from all sides.
I suggest you take some of the beginner lessons offered here for free.
The above post shows very clearly how insane the "game review" on this site is.
The worst move of the game is 7. - f6, and it does not even get mentioned in the "analysis". Instead of that, Ng6 and black is OK.
(Just to clarify: Justbefair's own comments are sensible, I have no quarrel with those.)
The above post shows very clearly how insane the "game review" on this site is.
The worst move of the game is 7. - f6, and it does not even get mentioned in the "analysis". Instead of that, Ng6 and black is OK.
(Just to clarify: Justbefair's own comments are sensible, I have no quarrel with those.)
A quick glance at the game shows that Black played a few poor moves, and white flawlessly- which is pretty uncommon for a 800 rated player.

Just have a longer look at the position after 9...fxe5
Ok, both Kings don´t have castled, but white has free lines with his white Bishop, with the Queen, the h1 rook can come easily to live, not long, and the Queen can go to h5 with check (in fakt, next move proves that).
The c4 pawn is hanging. And have a look at the pawn structure: white has a massive center and your pawns are shattered around (to doubled pawns, the center pawns are isolated.
If you have a look at your pieces: Stuck on the 8th row on theire original squares. The Queen only has two squares (compared with the white Queen which has 5 squares including a check. Or your Bishop: also two squares (and useless ones), the white Bishop: 5 squares, including one undefended target.
Or the Knights: Your Knight: two squares, one of it at the rim. White Knight: 4 squares (one on the rim) and it is also protecting his two central pawns.
Only this small analysis shows you, that your opening was a complete desaster.
You have to learn the importance of development. Start thinking in the following way: Where do my pieces have their best, means most powerful, places on the board (definitly not on their original squares). Also: how can I keep my pawn formation intact.
That would help, I think.