Question regarding National Health Insurance and address registration

Hello, I am currently doing a Working Holiday visa in Japan and I had a question regarding some administrative elements.

I'm currently planning to stay in Kawasaki for a few month, but after this, I plan to move around and probably won't stay more than 10 days I each places I intend to visit.
Do I still need to do an address registration in each of those places?
My second question is if I can pay the health insurance for multiple month in advance instead of receiving a bill to pay monthly, I've seen multiple site and other stuff mentioning that I can do it but I'm not sure about the info ?

Thank you in advance

by justanormi