Many GFI outlets will not reset if they do not have power to them. You can pull the outlet out of its box and check for 120 volts feeding it. If you do have that voltage there, probably a bad GFI.
If you discover any outlets using push-in connections, I recommend you re-wire them to the screw terminals on the side of the outlet. The push-in connections do not like the constant vibration that RVs provide.
2008 Itasca Meridian 37H & 2015 Flagstaff T12RBST
2011 & 2012 Len & Pat's "One lap of America"
27K miles & 41 states in 13 months - Woo Woo
Yellowstone Lake 6-1-2012