It's a little poorly explained. First, you make some ships. Fleets are usually limited by total collective mass, so making a variety of ships of varying weight classes is a good idea. You never know what the mass limit will be until you accept the challenge. Make a challenge or accept an existing one. Read back over some of the pages for examples before making a challenge, or wait for a new one to start. Download HyperEdit. It's a mod that allows you to teleport your ships into place at the beginning of the battle. Don't use HyperEdit once the battle starts. Do actual maneuvers. Post pics of your ships as you invent them. You don't have to do this, but it's fun to see what other people come up with! Read the OP for the rules once you actually start a battle. Also have fun!