Where will you actually be coming from? Los Angeles County is pretty big, and sure, if you're at the south end of it, Brookhurst in Garden Grove (north Orange County) is close.
Here's some stores no one's mentioned yet:
Next-Gen Games at Pico and Hauser in west LA. Miniatures are D&D focused also Games Workshop, and lots of hobby supplies.
Knight Ware Inc on Cahuenga at the south end of Studio City. I think their major income is running card game tournaments but similar description to Next-Gen although more board games and cramped, cluttered, and dusty.
Odyssey Games in Pasadena. Web site looks amazing. Have not been myself but a member of my RPG group just visited and shared photos. Lots of game tables; can't be all for D&D.
For hobby supplies, no miniatures, there are a surprising number of train stores in the greater LA area; google "train store near me". Same for "art supplies". For plastic models, "hobby store". Obviously if you're not here yet, search near the zip code you'll be based in.
goes to sea with the Terrain Mat.
