If you want to prepare your PC beforehand, I would
- Install Unity Hub. This handled multiple Unity versions on the same PC and is a life saver
- Install the latest Unity from (whatever it happens to be - there won't be any major releases soon AFAIK). Include all the UWP/Windows store things and the IL2CPP scripting engine support
- If you're more interested in doing AR for the tablet or phone, then install those SDKs too - it's really up to you what you want to get out of it
- Careful with the installer and it telling you to install VS 2018. There's a checklist here - but I wouldn't worry about the emulator. It sucks.
- Do a quick "Hello, world"