Last year at beaverun they held the Evolution Driving Schools. But due to scheduling conflicts and some other stuff they are going to skip a year. Some good general seat time outside of NHSCC is the Steel Cities region that runs up at beaverun. Also beaverun itself has some low key autocrosses usually held weekday evenings that are great to go and get a good numbers of runs in.
Just show up in a timely fashion, no pre-registration required.