Lots to do in Vegas
if, and only if, you're willing to spend some money. Not too much to do if you're looking for free things, but there are some. But most have already been mentioned. Hoover Dam/GCanyon, Death Valley, side trips; Various museum and exhibits.
If you're interested in either very fast and very expensive cars, there are opportunities to drive them. The two I've used are Dream Racing (
http://www.dreamracing.com) and Exotics Racing (
www.exoticsracing.com). Both are fine, but I prefer the former. I'm told that there are similar places for people with and interest in exotic guns. Not my thing, so it's purely hearsay to me.
Food in Las Vegas is much, much improved over the past 30+ years. There are so many top restaurants in Las Vegas that it's hard to even list them. But ones that are truly outstanding and much be mentioned include world renowned Lotus of Saim (Thai); and a branch of world renowned LA based Chengdu Taste (Szechuan). A few high end French places, too. Pierre Gagnaire is probably the best of those, though some would argue for Joel Roubuchon (the full restaurant, not Atelier, though atelier is fun. Both quite expensive and quite good. Aureole is also nice. Guy Savoy has now opened a restaurant at Ceasar's and I have yet to dine there. If it is anything like his Micheline three star in Paris, where I've had the please of dining twice, it will be an amazing experience, and should surpass Gagnaire.
Many less expensive options though those tend to go in and out of style and their quality isn't as consistent. But among that group I can personally recommend Yardbird, Roku, Honey Salt, Andiorn Steak and Sae, Bouchon, Chada Thai and Wine, and Sirio, Also check out Easter Las Vegas (
https://vegas.eater.com/) for up to date current information.