just because my area has such a high prevalence of parvo, i would never let my babies outside without all their shots. for example the kiddos could get parvo from a bird dropping a little bit of parvo infested poo in my yard, which my kiddo could pick up, eat, etc
i understand wanting to get the puppy started on potty training but i personally would not take this risk

this is per my vet and his advice. but all areas are different - so i think a well educated vet in your particular area would have the best advice