There is no risk from a handjob - hands don't transmit STDs. and there is no risk to your nipples.
The strains of HPV that affect the genitals can affect the mouth, but they only affect those areas.
Most HPV infections are not dangerous. There are strains that can lead to cancer, but that's most often preventable with pap smears.
HPV is transmitted by oral, vaginal and anal sex. It is VERY common. It's estimated that close to 90% of us will get it at least once in our lifetimes if we are sexually active.
There is a vaccine for it that protects against the most common strains. You should talk to your doctor or local STD clinic about getting it.