how do you plug christmas lights outside without an outlet

Well, there are a few ways to do it. You could use a generator to power the lights, but that's expensive and inconvenient. Another option is to use solar-powered lights, which are becoming increasingly popular. You could also use battery-powered lights, which are relatively cheap and easy to find. Whatever you choose, make sure to check the manufacturer's instructions and follow all safety guidelines to ensure that you're using the lights properly.