That depends entirely on you personally. You may want to tell those your closest to first (whoever that is for you) or who you think will be most helpful/accepting first. Sometimes people even tell an acquaintance first sort of to break the ice before telling the people that know you better.
Like bubbles said, that depends on your situation: how close you are with certain people, how open to gay people your family seems, etc. In most cases, I would recommend telling a friend first, perhaps a fellow gay person if you know any. Friends come and go throughout your life, your family tends to be more permanent, hence why most people have such difficulty telling their parents. My parents were about the 10th people to know if my life. Close friends (and especially gay friends) came first.
hi that´s totally up to you it depends what you feel it´s more comfortable for you If you think your friends will be more supportive or more educated on the subject you should tell them first, but it you feel your parents are better option, go for it I don´t know your parents or friends so that´s your choice, do what feels right/better right now. Do what you need Good luck and have a beautiful day