Also a good idea to read this list of common issues and fixes:
For the camera angle, the size of the bed is exactly half the needed info. The other half is how high above the workspace you’ll mount it. With aa 500mm wide bed, the minimum height for the 120 degree lens would be about 350mm above the bed. If you’re mounting it anywhere other than dead center, you’ll need a little more room for the camera to see the whole bed.
