How would you ask to keep the communication going? (More details)

I ask because I don't know how to make friends. It's awkward at this age. There is a girl, i assume my age, who I took a class with last semester. The class was very small. We sometimes talked on the way to our cars, unless one stayed after class to ask questions or something. Anyway, my "plan" was to try and befriend her this semester as we were scheduled to be taking another class together (this was not planed, we were just in a pre-requisite for an upcoming class). Turns out that she did not make it to the next class. In this new class( the one i thought she would also be in, we have to do an internship. So i emailed her and asked where she was gomna do it at. She responded that she wasn't goimg to be in the class. Anyway, I need friends, I see a potential ome so I need to say something before too much time passes...nowadays, you cant tell a persom " i think you're cool" or something withoit them thinking you're gay or something...

Advice?
Please excuse typos as I am on my phone