Ah, okay, that makes sense. Hard to say about the certificate. There are actual partner programs that are recognized by the Peace Corps https://www.peacecorps.gov/volunteer/university-programs/peace-corps-prep-partner-schools/ but none of them are in Maine, so clearly the school you’re talking about isn’t one.
Dental Hygiene does not strike me as a career for someone who doesn’t consider herself a people person. Not only do you have to interact with people all day, but you also have to hold up more than your share of the conversation! Medical laboratory technology would be a better choice, in my opinion, if you want something health-oriented.
The business and public administration programs sound broadly applicable, and probably have the option to go on to a four year degree if you decide to. That might be the best choice if you want to finish something practical, quickly, but also want a growth path.