Spin2Win moderators are chosen from amongst the moderator ranks. So, the best way to become a moderator is to make yourself known within the game chat. Be present for a collection of spins and make your wishes known to the moderators that you run into.
The moderators will be looking for people who are helping other players with their questions, introducing new players to the chat games and just keeping an eye on everyone staying civil and nice to each other.
The existing moderators pay attention to community members who step up and help out during spins. So, being a good community member is a great start.