So my school life is about to end and it kind of made me need it even though I've been through a self-improvement journey for the past two years and have reasonable confidence plus looks. So this is my last chance to have a high school gf and I regret rejecting two girls. our class consists of a few people currently only 3 chicks are available.

So a girl and I talk a bit we are interested in each other I've asked her on a date twice once I had to cancel so I think she took revenge. But she's also talking to another guy and she messes with him. She give him false hope a few timed. He is obsessed with her and he started dating this girl and he just dumped her when she said she's interested, I know personality is crap. But I'm not looking for anything serious and I have accepted the risks.

also this guy kinda fucked me over by talking shit about me to her and vice versa which was one the reason we lost interest in each other. I just want to date her for the sake of having a gf I don't care where our relationship takes me I can just walk away in a day. If anybody has any crazy theory or method they want me to try lemme know(I never though id say this but here we are, I know what im doing so ya)

tldr: how do I escalate with this girl after the interest kinda died a bit.