Some good first time experiences for people are Space Pirate Trainer if they like shooters or I Expect You To Die if they're more of a puzzle game type and Beat Saber if they like rhythm games. These games don't involve thumbstick based movement so they probably won't make you feel sick. If you want something that's really chill and is just kind of pretty to look at and walk through then Walkabout Mini Golf is pretty good, it's not the most exciting game but it does have multiplayer and it's pretty relaxing to play a round and just admire the work they put into the courses.

I've heard that setting up a fan so it's blowing on you while you're playing VR is a good way to prevent motion sickness. I don't really get very motion sick though so I haven't had to try it.

Some very good games that will definitely make you motion sick are Pavlov and Bone Works. You will feel queasy after playing these for the first few times, have some Gravol on hand just in case.

For better screen quality you can either use a Quest 2 or the Valve Index, you'll be tethered to the PC with the Index though which for me is a deal breaker.