Windows 10, this is: %localappdata%\Packages\Microsoft.MinecraftUWP_8wekyb3d8bbwe\LocalState\games\com.mojang\.If you used an imported skin, you can find them in \minecraftpe\custom.png of your internal storage. In Bedrock, unlike Java Edition, skins are a little messy there's several types of skins available Regular Skins
