What's a solo
If you enjoyed the Starting Line event, I would suggest signing up for a regional solo event! Occasionaly regions offer "novice schools" the day before an event, which you might also enjoy, but these are by no means required.
At regional solo events there are almost always highly-skilled autocrosses whose work assigment for the day is "instructor" who are there to ride along with you and offer pointers.
Most SCCA solo events are regional events and most of the participants at these events live within an hour or two of where the event is being held. Typically, regions that host solo events will do about one event per month during the "autocross season" which in my area (Upstate NY) is April through October.
The skill level of competitors at most regional events varies greatly. It is not unusual to have several people at a regional event who do only one or two autocross events per year and do it in the car they drive everyday. Many of them do nothing more to the car other than take out a the loose items. Some will even be first-time autocrosses. Standing in line with these casual autocrosses are likely a handful of competitors who travel hundreds of miles to national events one or more times per year with their dedicated autocross car and they are at the regional event to get some additional seat time and help hone the skills. And of course there are those of us who do as many solo days as our schedule will allow, traveling to the nearby regions, but not planning on doing any national level events.
If you are looking for events near you, you may want to check out
Pick "Within 60 miles (or 120), put in your ZIP, check the "Autocross/Solo" box on the left, and click the ">>" next to your ZIP