Yes, in order to add a camera and for other users to join your game, you must create an event. This can be done in the mobile app or, if you have an organization, on your organization page on the Sporfie website.
You can also add upcoming events to eliminate this step on game day. If you do so, it is important to make sure you change the location from your current location to the actual location where the game will happen. This will ensure that other users automatically see your event as they arrive at the game.