To register as pilot you have to fill the "Pilot register" form. You need to provide you name (HyperLobby callsign) and provoide a personal password. Additionaly you can fill your e-mail and a avatar image link. When this is done, you can edit you profile, join a squad, create a squad, etc.
Notice that if you have already flown a Airforce War mission you are automatcally registered as pilot. The password assigned to you is you hyperloby name (exact case). If this is your case, you have to skip registration, and go straight to "edit pilot" so you can change you password and complete you mail, avatar information. Then you can join or create squadrons.