Don't miss things -
one is the fountain show at the Bellagio, I always try to catch a few. they are every 1/2 hour in the afternoons and then every 15 minutes in the evening.
Another if it fits your budget is a Cirque du Soleil show. There is "O" at the Bellagio, very handy for you, and others on the strip as well. Zumanity is age 18 and over, the others are for all ages.
Dining is a highlight for DH and I in Vegas - there are so many wonderful restaurants that we don't have something similar to at home, so we always try to eat well. You can be really really adventurous or not. Most places have menus online to check out ahead of time (go to each hotel's website), and they are always posted outside the restaurants. Some are $$$$ and others are more reasonable. I would love to try Picasso and some others but am balking at the price, a friend suggested going just for dessert and coffee. I would have to pack DH's suit as it is one of the few Jacket for men and skirts/no pants for ladies restaurants. Most nice restaurants are business casual.
Window shopping at the Bellagio and the Forum shops at Caesar's next door can be fun. All these brands and designer labels I've only read about are all lined up in a row.
People watching is fun, Vegas is a weird town.
The Bellagio has a small but very nice art gallery. It's $15 to get in, takes an hour or so to see, the exhibits rotate, last time it was Impressionists, the time before was all Monet. DH was nice and went with me, but if it's another Impressionist in August I'm going by myself. No problem, I have a day and a half to kill while he's at a conference. The Venetian also has an art gallery and beautiful shops/restaurants but we've spent more time in the Bellagio as it's been closer to where we stayed.
Gambling, but I probably don't need to mention that one. I like nickel video poker myself, you can play a long time on $5. Make sure you bring $1's for tips. Drinks are free while you are gambling, but I like to tip the cocktail servers.