I really want a relationship, but how to get one?

ok im a 15 years old gay guy and ive never had a relationship before nor have i ever kiss a person.. no one knows im gay, but i really want someone now... i dont know how to recognize ifi someone is gay..so is not like i could ask some one just like that, the only open gay boys in my school i know are annoying ... so i dont know what to do... and even if i get a boyfriend i dont think i could tell my family .. and i domnt know how i would excuse my absenses..i dont know what to do please help