You're already doing the best thing you can do when you think your skills need to improve, and that's by practicing the thing you want to get better at.
That said! I'll point out one big thing that seems to be an on going problem you should nip in the bud- start using quotation marks for dialogue!
Original and rewrite bellow:
I slowly spoke have we met before I have always thought you looked familiar.
When I said that retracted his hand from my hair.
You don't remember? (Daniel)
No I tried recalling but I can't seem to remember so I thought maybe you are familiar to someone I know.
He sighed and said it's okay if I don't remember we met long time back so it's natural to forget and we were too young back then but it has somehow made him sad that I don't remember him.
Rewrite:
I spoke slowly, "Have we met before? I have always thought you looked familiar."
He retracted his hand from my hair.
"You don't remember? " Daniel asked.
"No. I tried recalling but I can't seem to remember so I thought maybe you are familiar to someone I know."
He sighed and said, "It's okay if I don't remember. We met a long time back so it's natural to forget, and we were too young back then." I could tell it made him sad that I don't remember him.
It's really going to increase the readability of your story to spend a little more time on punctuation around the dialogue. If I was you I'd go back through and edit the dialogue of each chapter, and while you do that you'll probably naturally notice little things you can improve on your own. Then you just keep going!