You're going to have to describe what you mean by fish house a little better. A structure with electrical requires a grounding system. Most breaker panels want to be fed by 240V . What size generator are you running?

i talking about an 10 x 15 ice fishing house. my generator is a 7500 watt.

So this is not a permanent structure, but something you drag out onto the ice for fishing? And what you want to do is to put in perhaps some lighting and outlets powered by your portable generator which would be outside?

From what I understand a fish house is more like an RV than anything. Instead of rolling it from campground to campground, it's rolled out on to the ice for fishing.

Obviously the generator needs to be outside the structure to prevent carbon monoxide poisoning. You'd use something like this (the appropriate configuration to match the generators output):

A cable (again, appropriately sized) from the generator to that "input" would feed your service panel. From there treat it as ordinary household wiring, making sure your demand doesn't exceed the rated output of the generator.