OK ---
Las Vegas:
The Strip at night, mostly between LV Boulevard/Spring Mountain down to LV Boulevard/Tropicana - above that, it gets skanky and below that, there's not much pedestrian activity. A good buffet is at The Mirage, it's in the low $ 20s. You might day trip it to Hoover Dam (about 20 miles). Just pick one show. Do not go too far east of the strip (not east of Paradise and definitely don't hang around UNLV or Maryland Parkway, it's gross). Your weather ought to be good in about 1 month.
Los Angeles:
If you see this city wrong, you may write it off.
The Westside: Sunset Boulevard from Hollywood and West Hollywood through Beverly Hills and out to the Beach, from there you can turn north to Malibu and then return to Santa Monica. Cheesy sights include the Chinese Theater and the Studios. This area is where LA's "people in the spotlight" live.
The South Bay is a great spot and includes Manhattan Beach, Hermosa Beach and Redondo Beach...at astonishing prices for cracker boxes. This is where people who are successful but prefer a laid-back lifestyle, but don't want to be too visible, live. Most tourists don't go here, but it is considered a great spot by those of us who grew up here. And you can see my high school as your plane lifts off from LAX...I always look for it and can see it.
Do you have 1 day for a day trip? Try Santa Barbara (95 miles or 150 km north, along the coast) OR Laguna Beach/Newport Beach (60 miles or 100 km south), but both are NOT doable in such a short span.
Enjoy and PM me with any questions or need for details.