HI Kathryn5284,
Welcome to the Heartland Owners Forum and to the family. We have a great bunch of folks here with lots of information and all willing to share their knowledge when needed.
The fuses, if on the 12v side are just automotive fuses, available at any auto parts or even Walmart or, are you thinking circuit breakers on the 120v panel. The GFI has a reset button on it. Can you till us what you did to cause this? Maybe we can get better help then.
Enjoy the forum.
Jim M