I wanna say something to this girl but I have no idea what to say or how to say it. [College]

So I intend to do something I have never done before. Ask a girl out. I met this girl today in my class, she looked super pretty, and she is so interesting and funny. We were talking (she shared her food with me- thank you) and I just wanted to be with her more. I wanted to hug her and give her my number and say "lets grab dinner soon?" but I couldn't say it. I felt like I was going to pass out. My palm got all sweaty, my cheeks got red and my heart began to race. I have never felt this way about a girl ever. I looked away and left. I didn't talk about her after to my friends because I didn't want her to think I was weird. I just want to see her again. I wanna ask her out on a date, I wanna say "hey, you look really pretty," but I have no idea how. I am such an idiot. I am just gonna forget about it.