Not sure about what to do with my life

Hey guys I’m 16 years old. I live in Spokane Washington. I’m having this problem with talking to my mom and family about theses feelings I’ve been having for a few of my girl friends. I think I’m Bi and it’s been just this year that I’ve noticed! But I’m not sure how to sit down and tell my mom. I also recently started basketball and I don’t want to tell her and have her think that’s the only reason why I joined or I don’t want people to think that’s why! I’m really struggling with this and i know I am bi for sure! My mom and family always joke and laugh about me and ask me if I am and I just don’t know what to say, I just there and say nothing and i feel like my heart gets stabbed every time they do!! I recently joined this club with y friend its GSA a gay, straight, alliance and it’s helps out a lot to know their are others too!! Well I told my mom I joined and she looked at me funny and said your not gay are you, well I went speechless when she asked and yet again I said nothing! Tracy and Stamie what should I do I dont have a clue what to do. And I don’t know how the whole dating thing with girls work either. I’m so stuck and I need some major help. I’m hoping you guys can help me out. Well thanks for your time.
Love Jessica mullen