Where can I find a warehouse/office type space in SoCal to rent for a small convention/gathering?

It’s for a meetup/brainstorming/educational purposes, for a creative/artsy online community. It has to be indoors, with some desks/chairs (worst case scenario I can purchase chairs)

It’s kind of an open-source/free discussion forum, so I’m just gonna pay it out of my pocket. It can’t be too expensive unfortunately. Maybe something like twice a month depending on how it goes.

We’ll be using laptops but power outlets would be nice. I know this is dumb, but I was thinking of renting a storage facility (but it’s probably illegal)