My dad built a house about 8 years ago. 8×16 with a 3 ft v front. Double doors in the back to haul atv.
He runs an extension cord from the generator to the fishhouse. Male plug on the outside of the fish house so all he has to do is plug the cord in.
2 deep cycle batteries inside hooked up to an onboard charger. Generator really is only needed to charge the batteries, run the microwave (rarely used), and TV.
He ran all the wiring before finishing the inside so there are no cords showing anywhere. Only bad thing is he clipped one of the speaker wires with a finishing nail, so he just bought a sound bar instead of tearing out the ceiling to find the bad spot.
It is a process building for sure, but fun if you enjoy that kind of stuff. Great feeling when you can build something like that and then go out and use it and be successful.
Really think and plan on what is important to YOU. Are you a hardcore fisher? Or is a TV and comfort more important?