The most common things to check on Android
- Make sure the camera is set on all the manager/helper objects
- Check that you have added the android permission helper script and set it to allow the camera.
- In Player settings check the minimum api level is 10 or higher.
- In Player settings ensure the scripting backend is set to ilcpp and that the target architecture is set to ARM64
- If you are still getting a black screen try setting the blit type to auto under Project Settings->Player->Resolution and Presentation
- If all else fails you can download the getting started project file from the dev portal unzip it and open that in unity hub with the add button as this is a project that is already configured.
And remember we currently only support 2019 LTS versions