You can adjust or turn off most settings in the settings section. Just click ‘more’ in the in-game menu (it’s to the right of the chess board in any game) and choose ‘Settings’.

Here you can adjust most settings, including the board style, sounds (on or off), auto-queen promotion, indication of the opponents move and more. You can also ask Arena to show (or not) legal moves.

Once you finished setting up the playing space, just click ‘Done’ and the settings will be saved. You can change them anytime.