what should i do with this girlll?

Okay this is very corny so here i go. I met this girl a couple months ago and we went to prom yesterday and a concert the day before. i've been nervous cause i want to make a good impression and i also like her. at prom she danced with me a couple times but danced with her best friend majority of the time. i also decided to dance with other girls but lately all i have been thinking about is her and its all i want to do. Now im not sure if i like her still because of prom and i still do because we have a lot in common. the problem is if i tell her, i completely risk ruining our friendship and if i tell her and she likes me back, i like longer, serious relationships and she's going away to college in a couple months. I just don't know if its worth telling her and i've been sick to my stomach the past two days just from thinking about her(good and bad). im 16 so i have no clue if semi long distance relationships are worth trying if i were to get to that point in time with her and im most likely not in love but just crazy for this girl. what do you guys suggest i do?