Congratulations! A 30 minute game here which is a good time control because you have time to think carefully and avoid blunders - however you spent just 4:30 on the entire 30 moves. That's an average of 9 seconds per move and because you are a beginner you are going to miss a lot of things if you move at that speed. 2 major blunders:
6.c4 leaving your knight there to be taken by the pawn.
9.Qb4 placing your queen on a square it can be captured by the Bf8.
If you slow down you will see these things. No advice can help you when it comes to stuff like this - it's about looking at the whole board and taking a bit of care. Middle game play and indeed any other facet of the game are irrelevant whilst you are losing games because of simply losing your pieces. You must get to a point where you very rarely/never do that before you can hope to improve.
I'm a beginner at chess and I finally won my first game. After losing game after game I got a win. I want advice on how to improve on the middle game and avoiding blunders.
Thank you for any tips and advice in advance.