The 610 bus run by Uno will take you to and from both campuses.
Currently they and just about all routes are running to an amended Saturday service, what will happen when the school and UH term times start I'm not sure at the moment, because as we know due to the C19 pandemic things can change very quickly, including the way of working at the UH itself.
The Uno website
www.unobus.info should give you some idea of times and ticket prices. What sort of ticket is the best obviously depends on your UH contact time and personal circumstances of course.
Hertfordshire County Council also have their own comprehensive travel site "Intalink" ( see my previous posts) including all timetable and corona virus updates.
Uno have fitted hand sanitisers on their buses by the way.
At the moment the government is propping up funding on many of the bus routes, as due to the massive shortfall in passenger numbers coupled with enforced social distancing reduction per bus passenger càpacity, they simply would not be economically sustainable. I understand this will continue, albeit with a reduced amount, from October onwards when current funding levels come to an end.
As soon as I hear of any further timetable developments I will keep you folks posted.
Excuse delay in reply.