Summer league is typically held at the UNLV facilities, which aren't that far off of the strip. I've never personally bought tickets, but the games never sold out (pre-COVID at least), so I would imagine you'd be fine buying tickets on something like stubhub if you don't want to commit ahead of time. ("Honestly, honey! I'm just going to watch a basketball game!" - end up on a Hangover adventure).
Where to stay depends entirely on your budget, but also should depend on how much time you plan on spending at the hotel. I can recommend something like The Venetian but if you're going to be out watching games and exploring the city, then something like the Flamingo at a fraction of the price makes a lot more sense. If you can get a room at Caesars that faces the Venetian fountains, consider that.
Big takeaway from my last trip was to eat off of the strip if you can as strip restaurants were jam packed. Highly recommend Zenaida's Cafe if you want good food at a reasonable price and don't want to wait an hour and a half to get served. Family joint with a qualified chef and a polite staff. Peg's Glorified Ham and Eggs has a pretty epic Monte Cristo, but probably not worth the wait if you go on the weekend. Been eating there since they only had one restaurant. The original Peg still has beef with me for putting too much ketchup on her food.
