Do you have to change your settings on the Avata 2 using the goggles. Is it possible to switch everything on and then connect your phone to the goggles and change the settings on your phone before you put the goggles on

You have to use the goggles. IIRC DJI Fly app even tells you that if you try to tap the screen while in live view from the drone.

Hi there. You can only do the following from the DJI Fly App when connected to the Goggles 3:
• Discover recommended Fly Spots, check for GEO Zones and find information about local laws and regulations, watch function tutorials, and read product manuals.
• Visit the album to view photos and videos, or explore more shared footage from SkyPixel.
• Log in with your DJI account to check your account information and flight records.
• Update firmware, locate a lost aircraft using Find My Drone, visit the DJI Forum, or shop the DJI Store.
• Display the video transmission, which allows you to share the FPV camera view.
Have a nice day.