>>278588019
Welcome to VR anon, enjoy your stay.

The steamvr boundaries don't matter and you can turn the indicators off (should be automatically?). The oculus guardian ones will still show up in steamvr games.

I don't know if the Rift S still has the green cross calibration screen, but >>278588228
 is right, adjust up/down then left right. Use small text or something else to judge blurriness if the green cross isn't there. You can measure your IPD yourself to see if it's in range, and you can buy custom prescription lenses for the headset if you want.