how do i change my main class

[KoroushSensei]

where is this control panel? i checked forum and ffxiv character settings and nothing

[SpiritMuse]

At the top right of the screen next to the big blue "Log out" button it'll say "Welcome" and then your name and underneath that "Settings" and "My Profile". Click "Settings". In the next page there'll be a column on the left side with, among other things, "Edit Character". Click that, and that'll take you to the page where you can select which character you want to display (if you have more than one) and what classes or jobs you want to show.

Hope that helps.