Acme Acres is the fictional city where Tiny Toon Adventures takes place. All of the characters live there, with the exception of Gogo Dodo. Also it is the location of Acme Looniversity.
Location
The actual location of Acme Acres doesn't seem to be firmly defined, as it has been shown in multiple locations in various episodes, but it appears to be most commonly placed in California. In both the cartoon, "Cross Country Kitty" and in the Tiny Toon movie, "How I Spent My Vacation", it is shown in California, probably near Los Angeles. However, in the cartoon, "Never Too Late To Loon", it is shown as residing somewhere in Missouri.