You must join the server by pressing the button "Join the server" above and contact the staff, or the user that made the staff listing.
I need 3 people for my server's promotion team, you get access to most staff channels and have a change of being in special videos of mine
You will have to have multiple advertising servers to advertise in plenty of places. The server has its own custom server ad that you get to use to promote the server. With the special videos as a promotion team staff member you have a higher change then some of the other staff to be a part of multiple videos.