This is being produced by someone who has never played the Arena. My first attempted experience resulted in missing registration because I was looking at the cool art of the red room you get put into when you type /join. :-P When I saw notification that the Arena started, I noticed everyone in the red room disappeared. I looked around for stuff to click and found a table that gave me betting options. Was told everything is temporary BUT... Unlike the rest of the Arena stuff, the money isn't temporary. It's your real in-game money.
Guess you register for the Arena by clicking on that table in the red room.
Once the Arena starts (if you registered), you get teleported to your own temporary island. Everything you had in your inventory is temporarily stored in an invisible space. Don't worry about storing your inventory items. You are given new inventory that matches everyone else. You are also given new stats to match everyone else.
Fish? Don't have to bring your own fish. You will have to do your own fishing and cooking once the Arena starts.
Armor? Don't have to bring your own armor. You will have time to make your own armor once the Arena starts.
Weapon? Don't have to bring your own weapon. You will have time to make your own weapon once the Arena starts.
Once the Arena is over, you are teleported back to the RPG MO world. All of your previous inventory items are restored.
I also did not compete i was teleported but i lost connection