The improvement you need is actually not that great.
Your opponent played with a single purpose- to mate you.
Thus you see moves like Bd3 , Bc2, Qf3, Qe2 and eventually Qd3 are all played with one aim- lining up the bishop and queen to attack your king.
Had you noticed, you could have stopped him easily.
But you didn't notice, and so got mated.
You need to play with a purpose. Trying to mate your opponent is a good one.
As you get better, you won't be able to be so direct. Such direct attacks are often easily repulsed.
But for now you are still at the stage where thinking about what your opponent is doing is not something you do.
On move 2, your opponent played Qh5. Do you ask yourself why? What is the threat?
Does Nf6 stop it?
No.
Look at Qd3. Did you not see the point of all those moves?
Hello, I'm terrible and I heard that it is better to have my games analyzed by a person instead of an engine. Okay, my rating is at around 500 and I've improved to the point that I don't get my queen captured now I have to get to the point that I actually win or draw. I don't know how to actually annotate games real well, but here's the game. I know that I need to learn how to slow down and think things through on slow classic games and I'm horrible on 5 or 3 min. games. I usually play the Ruy Lopez on White and don't play to well on Black and currently trying to learn the Sicilian Defense.