The most important component of a successful movie night is the projector. An outdoor projector is going to be different from the one you have inside. You'll want to find one that's small, portable, and easy to set up. Typically, these projectors will support HD resolution, or thereabouts, with a decent throw so that you can set up the device between 10 and 15 feet from the projector. Brightness of 3,000 lumens should be efficient, though you won't want to go any lower. If you're in a space where there will be some ambient light, then consider a projector that's brighter. You'll also want a projector that can achieve a screen size of 100 inches or more, and that should cater to anywhere from five to 10 people. My go-to is the Kodak Luma 150.