How to escalate with a girl in my class?

We both sit next to each other for the past few weeks (seating arrangement). We get on quite well, and there are some signs of interest. How can I progress it further? I understand that being friends / getting to know someone should come first, and it's an ideology I believe in, but how do you even do this without friendzoning yourself or on the opposite end, being too forward?

How to escalate with a girl in my class?
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