In Hillsborough, your utility is going to be Eversource Energy.

That is the only choice you have for who physically delivers the energy and will be who you pay your electric bill to.

You are however allowed to shop for different energy suppliers, which may allow for a lower rate overall or may not compared to just letting Eversource take care of supply.

Be extremely careful in doing so as the lower rates are oftentimes at the cost of higher risk (for example you may end up paying for electricity as a spot price depending on market conditions which can have crazy spikes, instead of a flat rate, etc). A number of suppliers are bona fide scams so be sure to read reviews.