The McDonalds scenes were all shot in City of Industry, CA, just outside Los Angeles. The set was an actual McDonalds built specifically for crew member training and filming television commercials. Everything inside worked, but it never served a real customer. When it wasn't being used, it was locked up behind a chain link fence. From its construction to the day it was torn down, it was never open to the public.
When Paul Rudd appeared on Late Night with Conan O'Brien (1993) he liked to play a prank. He'd set up a clip of his upcoming movie and say he was going to have it played for the audience. Then he would show the scene from this film where Eric falls into the water. Jennifer Aniston, who made her feature film debut in this movie, went on to costar with Rudd in many projects, including The Object of my Affection, Wanderlust, and "Friends."