What hotel are you staying at? I just went on vacation there with my family. There are a ton of fun things to do in Las Vegas. My favorite parts are the shows and buffets. My parents booked a trip on a site called Las Vegas Direct that got us a good deal. You can get a good price on show tickets from a place called Tix4Tonight Half Price Show Tickets Just be sure to go in the afternoon to get good seats. They have stores around the hotels. Be sure to see the Bellagio Fountain shows, they are free and so wonderful. We also saw Hoover Dam and did some hiking at Red Rock which was awesome.
I went to San Diego a few years ago. Biggest thing there is SeaWorld. Had a lot of fun and hope you enjoy it! There are a lot of good restaurants too in what they call the Gaslamp Quarter which is a historic part of San Diego that you must see.