We're provisionally at the Cosmopolitan, due to decent rate for 2 rooms and proximity to the arena - but it's free cancellation for a while so looking at other options periodically.
I signed up for ticket alerts from VGK here:
https://www.nhl.com/goldenknights/tickets/single-game - I said I lived in Vegas, and got an email from someone to discuss 10-12 game ticket packages - on the fence there as resale will probably be great in year one, but it's likely I'd miss out on the B's game. More info in August I suppose.
I went to the Hoover Dam when I was 12 with my family, that wasn't too far. I think Death Valley is pretty close as well. That's about all I got for day trips though - I'd love to get out and golf around there a bit but this trip'll be too short I imagine.