Vegas is one of those places where you can mix big attractions with random fun, so I’d say hit the Strip at night (just walking through the themed hotels is half the experience), catch a good show like Cirque du Soleil, try a buffet or a nice restaurant, and spend some time at a casino even if it’s just for the vibe; if you want a break from that, the Fremont Street light show is great, and a quick trip to the Grand Canyon or Red Rock Canyon is totally worth it. I personally enjoyed just exploring different hotels and people-watching the most.