Pre baking a galette

Yes, I think you could easily do this. Go ahead and assemble it as you're going to, preheat the oven, then bake it for about 3/4 of the baking time. You need to gelatinize the proteins in the crust, or it will go soggy on you while waiting to be finished. Remove it from the oven and cool it completely before wrapping it securely in 2 layers of plastic wrap (if it isn't completely cool before being wrapped, again, it will turn soggy from steam). To finish it, bring it to room temp before baking to finish.

*par-bake

Sure, pre-bake. I'm not sure what term to use since I've read it being used interchangeably in many recipes. I would basically like to know if there's a way I can make my galette ahead of time (the dough and everything formed together) rather than putting it all together a couple hours before serving. Ideally, I would like to make it 2 days ahead of serving.

By pre-bake, is there a chance you mean par-bake? The latter means that you bake it part way in the initial bake, then finish baking at a later time.