What is correct process for even getting to bios screen?
When the Beelink GTR9 Pro powers up you should see on screen the Beelink logo (center) and a BIOS/UEFI message (down and left) noting the “DEL” key to go to the BIOS/UEFI setup screen. Typically, when that logo/message initialisation screen is presented, hitting one of the “ESC” or “DEL” keys multiple times should take you to the BIOS/UEFI setup screen.

Or you could follow any of the available Beelink GTR9 Pro tutorials which show how to enter the BIOS/UEFI screen.
How do I get proper support in US?
In the same way as everyone everywhere else. Have you tried searching for any of it?