This new street food park in the shadow of the freeway has rotating trucks but a permanent site, with nice restrooms and seating for 100 in a large open "barn" where we can sit down to sketch in any weather. We'll start at 11:00 when it opens so we can stake out a good spot, and then pick up food and drink as we feel the need.
Read more about it at http://somastreatfoodpark.com/
Bus lines 9, 27 and 47 go right by there. The 12, 19, 22 and 33 buses will get you within two or three blocks. From BART your best bet is to take the #9 bus from Market Street in front of Civic Center station. There is a bike lane down 11th Street, plus a lot of others in the area. I don't know what the parking situations is, or whether you can use the Costco parking lot across the street.