Folsom Lake would be one of the only areas I'd consider. There are several camping areas in the Delta, but you're a good hour from downtown. Auburn has a quiet, nice campground. Folsom will be more like "camping". Auburn used to be a KOA, but is now an independent private CG. I would stay away from anything closer to Sacramento. Auburn Boulevard (not to be confused with the CG IN Auburn, or Folsom Lake which is ON Folsom-Auburn) is full of long term high crime campgrounds. Stockton Boulevard has many "campgrounds" as well, but a slightly higher crime rate.