This auto team script does not team anyong besides models. Would love some help (Should be easy?)

You must format your code correctly so that your code is readable. Otherwise, you'll have no idea what you're writing:

game.Players.PlayerAdded:connect(function(player)
        if player:GetRankInGroup(2533886) == 8 then
                player.TeamColor = game.Teams.Security.TeamColor
        else
                if player:GetRankInGroup(2533886) >= 1 then
                        player.TeamColor = game.Teams.Models.TeamColor
                else
                        game.Players.PlayerAdded:connect(function(player)
                                if player:GetRankInGroup(2533886) <= 0 then
                                        player.TeamColor = game.Teams.Spectators.TeamColor
                                else
                                        game.Players.PlayerAdded:connect(function(player)
                                                if player:GetRankInGroup(2533886) >= 12 then
                                                        player.TeamColor = game.Teams.HighRanks.TeamColor
                                                end
                                        end)
                                end
                        end)
                end
        end
end)

This "pyramid" look is not a good sign. Having :Connections inside :Connections is not a good sign.

Right now, if you just read what your code does, you only start waiting for rank 12s and beyond AFTER

• a rank not 8 joins
• then a rank 0 joins
• then a rank not 0 joins

Use either separate :Connections for each rank, or more simply, an if...elseif chain inside a single :Connect handler