Our region locally used to have a solo school at the beginning of the season. Format typically is like 10-15 runs day and you get an instructor who will ride along and maybe even drive your car to show you where it may go faster. We haven't had that for a few years though.
More nationally SCCA have a "Starting Line" Program which is usually organized with local region where they will send instructors and do an organized "school" for a day:
https://www.scca.com/pages/sl-autocross
It's not cheap but its actually decent value with what is included. I've volunteered for one and I feel like this school is great for absolute beginner since it has specific exercises for the more typical elements you will see at an event. And culminate in the end with a full course that will help you apply thing things you learned. Unfortunately I think most of the Starting Line School this season have already been completed. You have to wait til next year to see the schedule.
Another one not run through SCCA is the Evolution Driving School:
http://evoschool.com/
Similar idea, but I think this is more focused and can benefit from having SOME autocross experiences. Their schedule is on the site. They also run some smaller school in conjunction with the National Tour events in the area. I've taken the Phase One school and when I did it I've autocrossed for about 2 seasons on and off and I find that to be quite useful. Looks like quite a few California dates coming too.