Can i get hpv by receiving oral just once from a guy?

Extremly unlikely: HPV is rarely if ever transmitted mouth to genitals. It can be acquired in the mouth by oral sex, but rarely goes in the other direction. However, you can expect to have HPV someday; almost all sexually active people are eventually infected, mostly from genital or anal sex, not oral. That's why you and all young people need HPV vaccine, to prevent infection with the most troublesome HPV types.