What do we do if my bf has been w someone w hpv? We haven't had sex yet. I've had the 3 gardasil shot

Look for other STD's. If 2 people haven't had sex but know about each other's contact with hpv+ people, that means the couple talks about std's (communication is good!). A man can get Gardasil to prevent getting the 4 vaccine strains, but the shots won't get rid of hpv strains he already has. More importantly, the couple is talking, so they can go together to their doctors to be checked for other std's, like chlamydia.
No HPV worries. Almost everybody who has ever had sex has "been with someone with HPV". At any time, up to half of all people have genital HIV. So your bf is no more risk to you (in regard to HPV) than anyone else would be; the only difference is that he happens to know about a past partner's infection. Having had Gardasil, you're immune to at least 4 and maybe 9 of the most troublesome HPV types. No worries!