I [16 M] have a huge crush on a girl [16 F] and I want to start a relationship with her, how should I proceed?

Hey there!

I want to progress my crush to a relationship, but I'm not sure how. Looking for tips and advice.

tl;dr:

I have a huge crush on a girl I know at school. We used to be very good friends a couple of years back and now I have gotten somewhat older, I have an interest in her and want to start a relationship with her.

I have recently begun talking to her again over text because I am too shy to talk to her in front of her friends as they intimidate me. Right now we are catching up but I am not sure about how to do this relationship stuff, as I have never been in one nor had much interest in them prior to this. I don't know much about this stuff, even flirting is foreign to me, it really just comes out awkward.

When we were texting, I asked if she was happy with me just suddenly coming back into her life, and she said she enjoys talking to me, but she doesn't initiate conversations with me. She is a cute girl with a kind and caring personality and I want to try for a serious relationship, but how should I move forward?