Mmm. You don't have to be anything, if you don't feel so inclined. You can just be a person who loves people for being people, rather than for being a gender.
Maybe at this stage in life, you could just do a bit of experimentation. Don't pressurise yourself to try and make a decision, or to make that decision to please other people. I honestly don't believe that sexuality should be an issue, and for some people it can be quite a fluid thing, which is absolutely fine.
My limited advice would be to listen to your gut and your heart (whichever does the governing for you, I guess) and not to feel guilty about your decisions when it comes to who you have relationships with. Just treat people with respect and love, and what you are doing won't be wrong.