Hey you want advice since you have a crush on your bff, to see if she is straight or not just honesty say to her you want to know more about her and see if she is straight or bisexual or something, and once you know, start showing sighns like hold her hand then laugh and say "just kiddinggg" or like look at her and smile and be like "Hahahahaha" and stuff as like a joke and ask her if she has an actual crush, and let me know about anything by then
~Eboni x