You don't know how to come out? I just think it naturally happens. You surround those you trust after a while. You don't have to plan much it just happens friends will get to see the real you and most likely be a supporter however some may leave but you have to understand that they weren't genuine or true to you. Also about your family. I think once you have a relationship with a girl and that girl proves she cares and loves you, your family should open up more. Hopefully they'll see the honesty and kindness your girlfriend has. They I hope will see their relationship through your relationship. :) 

I don't know but I know this stay true to yourself and always be strong! You won't be happy if you try to please people. People that are good friends are people that appreciates you for you! You don't have to change yourself to be loved! Your family I hope will see the beautiful loving daughter that they always had, if they can't see that, go ahead with your life. No shame in loving another human being :)

Anna