In 2015, a Pomona newspaper/website wrote about how Beck used to busk around the city in the early '90s (it's not too far from Los Angeles). They specifically noted a show in 1994 at a coffeeshop, but before he got there, they mentioned him playing Munchies, "a sandwich shop whose back room was a bar with a small stage, paneling, Astroturf carpeting and a capacity under 200." Occasionally touring bands like Sebadoh or Superchunk would show up there.
Superchunk's manager, Brian McPherson, was from the area, and had signed Beck to a publishing deal, so he would bring Beck to see the "crazy local acts." At one point in 1993, Beck went to see Diskothi-Q and Adickdid do a gig there, and asked if he could play between acts, and he did 3-4 acoustic songs.
Side note, one of the members of Diskothi-Q was Peter Hughes, who felt bad for Beck having no audience, so sat and watched him in support. He was impressed right away. They became friends, did some shows together, and Hughes released Golden Feelings on his label Sonic Enemy.