I don't want to do HPDE event as that has little in common with a Lemons race.
The traditional path to racing pre-Lemons was HPDE beginner, then move to HPDE advanced, maybe try autocross or time trials, then race school and licensing, then racing. Lemons turned this on its head- now with just a driver's license you can go racing! That's been awesome and exposed a lot of new people to this intoxicating sport.
But once you're hooked, it makes sense to build your foundation. Saying "the only way to get better at racing is to race" is like a beginning skier spending all his time on the triple black diamond runs to get better. It may work, but probably won't, and is guaranteed to be a long and painful process.
If you know you love this and want to get better, going back to the fundamentals will pay dividends:
1. Basics: seating position, hands, shifting, heel/toe, mirrors, flag locations, situational awareness on closing speeds, flags, not having tunnel vision, lead/follow to get the basics of the line, etc. HPDE is great for this. Nice controlled environment.
2. "The line": braking points, threshold braking, turn-in, apex (late/not), turn exit, acceleration out of turn, where to focus on improving time, basics of passing/being passed, driving at limit, using the whole track to increase turn radius and carry more speed, putting together a "qualifying" lap, etc. Again, HPDE is perfect.
3. Racing/racecraft: Positioning on track, setting up for the pass/being passed, maintaining rhythm and flow, closing speeds, driving on limit in traffic, etc. Lemons is great for this, and review of your in-car video by, e.g., Racers 360 is great for this.
I've read great things about Racers 360. Given that this site recommends it, it may not be cheap... https://rennlist.com/forums/racing-and- … rvice.html
I've seen good racer/instructors at NASA events. 2 days at Sonoma (my local track) in HPDE is $350, for about 3 hours of track time. Seems reasonable. Ask for a real racer for some instruction.
I also think Harry's Laptimer is a great, inexpensive teaching tool. It's an app that takes advantage of your phone's GPS- $20 and you become your own instructor! How's that work? Drive around the track and Harry records your laps. Set one as your reference lap, or better yet, have a friend or instructor set a quick lap. As you drive more laps, the timer is giving you immediate feedback on whether you're going faster or slower than the reference lap. Go into a turn with the same time, but come out behind? Whatever you tried in that corner slowed you down. Now try different things to see how they affect your laps, or review your video (Harry can do that and overlay data) to see where you can improve (g force, turn angle, throttle position, etc. can all be monitored with a cheap Bluetooth OBDII dongle). Ideal for HPDE self-improvement.