Wouldn't this be covered under the background? We already have a hermit, a scholar and a folk hero that can fit in this.Only to whatever degree they're not accustomed to it.
For example, any non-human that lives in houses rather than wandering around the world without any kind of place to take shelter from a storm would understand what a house is, and recognize the idea of trying to keep it safe, clean, and intact, so wouldn't bust down doors "Because it was in my way? Am I not supposed to do that?" or shatter windows in order to open them.
Any non-human that wears clothing to protect itself from the elements or engage in modesty is going to understand how clothing works and even if they don't know the particular way humans connect or color-coordinate their clothes for fashion, they're not going to be stunned at the idea of "Cloth?! ON BODY?!"
Unless they exist in an entirely anarcho-communist society, non-humans are still going to understand that there are laws and people who enforce them and people who are in authority over other people in a human society... just 'cause, y'know... S'how so many societies work.
The individual customs? Sure. It'd pretty much be no different than flying to Japan without learning about the social faux pas you can commit. You'll step on some toes and be a bit annoying, for sure, but that only works if your culture and the other one have so little contact that you don't know even cute trivia about the other culture involved.
I'm not sure if we now have something where we need to look at human hermits and non-human hermits? Is an elf hermit that different that a halfling hermit, or a dwarf hermit? What about a mountain dwarf hermit or hill dwarf, or even gold dwarf? Not sure if we want to get that far with character generation.