How Can I Tell My Parents That Im.... ?

I think you have already shown it is not hereditary and maybe 14 is on the young side to be taking those feelings so seriously. Just have friends. Your parents are probably like most others and will see how things turn out without giving it a lot of fuss and that's okay. Be a kid. In all likelihood your parents are more in tune than you think and if it appears you truly need guidance just trust they will be there with a plateful. Take care. Jesus Saves.