GrimPanda, I looked up "Tennessee sign language classes" and I got this link, which has a bunch of links on the page that might be useful to you. I don't know where you are in TN but it has many places that offer sign language classes in different parts of the state
https://tndeaflibrary.nashville.gov/services_filter?tid=70
I would just go up to her and introduce yourself. Have a pen and paper with you. Say something like "Hi, I'm GrimPanda, what's your name" when she responds, either by ASL, voice, or writing it down, you can then say something like "I would like to be your friend, but I don't know ASL. Would you help teach me?" Also, if she's using ASL, does she have an interpreter, someone who is in the class and signs to her what the teacher is saying? If so, you can introduce yourself to her when the interpreter is there, and it can make it easier for her to understand you.
