Here’s the House Finch (Carpodacus mexicanus). This one came and sat on the back fence. The have a long, warbling song that is quite distinctive and loud.
These little birds would forage on the ground under the sock for the seeds that the Goldfinches dropped. Below is a female. I never saw a Goldfinch do this.
The picture below is a bit of a puzzler. The size of the red bird and the brown ear coverts seem to point to a Cassin’s Finch (carpodacus cassinii), which is very similar, although lager than the House Finch. They do winter over in this part of SoCal.