Gave oral sex to guy that i don't know his status my concern now is hpv how likely is transmission genital to oral hpv on a single encounter? am i at risk of any kind of cancer? is common this kind of transmission?

It is uncommon but it may occur. People with oral HPV is at risk of HPV-associated head and neck cancer. Please practice safe sex for avoiding these risks. Take care.

It is very likely. Exact percentage is not known for it depends on the infectivity of the virus and your immune system. Cancer only occurs in some people with a long term infection. Pl get checked if worried and in future pl avoid such encounters