Before starting Assetto Corsa Competizione in VR mode, we recommend joining the game in standard mode (on screen) and double check your controls and options. After this, you are good to go!
To center view in VR, please press CTRL + Space
In-game navigation is possible via Gamepad or D-pad. Again, make sure you configure your navigation and enter/back keys in regular rendering mode BEFORE launching VR.
In Documents/Assetto Corsa Competizione/Config/ you find a vrSettings.json, where you can edit the ingame HUD and the UI, including tracker lock and draw size.
In-game keys are CTRL+left/right to move forward/backward, and CTRL+shift+left/right to scale up/down. Your settings will be saved in the aforementioned vrSettings.json file.
Cycle press F2 key in-game to cycle to the HELP HUD, where you can also see the hotkeys.