Main Ranks: Builder, Resident, Mayor, President, Tycoon
Nether Ranks: Survivor, Warrior, Terminator
Aether Ranks: Pilot, Captain

Builder is a starting rank for users. You are already a Builder once you join the server. To become Mayor, you need to become Resident first and then become Mayor.
Resident costs 15k ecodollars. Once you have the money, apply in the Builders+ section. More information can be found in the wiki.
Mayor costs 85k ecodollars. Once you have the money, apply in the Residents+ section. More information can be found in the wiki.

To create warps, you need to apply for Town Warp Application which will cost 40k ecodollars.

To have multiple set homes, you will need to donate for Multihome donator feature which costs 15 usd. This allows you to set up to 5 homes.

Moderator applications are open once every month. You will need to become at least Resident to be able to apply for it.

To join towns, contact the mayors/presidents to buy a plot in the town.

All clans are in the Clans/Teams Discussion section. You need to become at least Resident to be able to join clan in server.

Hope this answer all your questions.