Jim (Adam Sandler) mentions that he manages a Dick's Sporting Goods store in Ridgefield. Ridgefield was the name of the town in which The Wedding Singer (1998) was set. The Wedding singer also starred Drew Barrymore.
The name "Espn" for Jim's (Adam Sandler's) daughter (Emma Fuhrmann) in the movie came from Adam's visit to a barbecue restaurant in Boca Raton, Florida. The owner had pictures of his kids up, and one of their names was Espn. Adam thought it was a really fun name and asked the owner if he could use it in his new movie for one of his kids. Obviously, the owner was happy to oblige.
The Lost City (at Sun City), where the families are staying, is adjacent to the Pilanesberg Game Reserve. This game reserve is home to the Big Five (lions, elephants, rhinos, buffaloes, and leopards), as well as zebras, hyenas, giraffes, hippos, and crocodiles.
In the scene at the little league game, they state that the pitcher for the opposing team looks older. This is a reference to the adult pitcher in the movie The Benchwarmers (2006), which was produced by Adam Sandler's company Happy Madison Productions.
The character at the shop who kept repeating "Hi I'm Tom", is taken from 50 First Dates starring both Barrymore and Sandler. Tom only has a 10 second memory in 50 First Dates, exactly like the same Tom in Blended.
The trivia item below may give away important plot points.
Jim goes over to Lauren's to profess his feelings for her, only to meet Lauren's ex-husband who tells Jim that they are getting back together. This is a reversal of the scene in The Wedding Singer (1998) when Julia goes over to Robbie's to profess her feelings, only to meet his ex-fiancée, who gives Julia the impression that they are back together.