There's a lot to learn, starting with the driving, then onto the maintenance and set-up, and even the media and thinking about sponsorship.
Learning to Drive
Learning to drive fast is best done in a low-powered car with no electronics to cover mistakes. This is just what Ginetta aims at with the G40 and the GRDC championship. So what do electronic controls do? Stop you spinning, primarily, which I found out as soon as I got into a Ginetta on a damp day at Silverstone. I'd only ever spun a car once before, but on the day at Silverstone I must have spun four times at least. My mistakes were either applying power too much and too early, or holding the lock too hard on the exit of a corner. In my 911 and even in my C230 daily driver, the stability management system controls excessive power inputs to the driving wheels so that it's actually difficult to spin.
After six track days in the G40, I'm slowly finding the speed. Taking the racing line and hitting the apexes is not a problem, but maintaining momentum through the corner is my challenge. On a wet day, that's even more difficult, until you learn the limit of grip in your car and your set-up. Even then, there are spins, but you have to show a certain amount of aggression (or assertiveness, as instructors like to call it), so spins and track excursions will happen now and again.
Primarily however, I remember four cornering principles when going around, plus the mantra the MSA teaches you when taking an ARDS race licence: speed is a combination of smoothness, accuracy and consistency.
On a car like the G40, you can adjust many parameters that will affect handling. The easy settings are tyre pressures, damper return / bounce, and anti-roll bar stiffness. The latter will have a big effect on your understeer or oversteer and the first two will also affect steer and levels of grip and feel. It's not at all simple, and I have adopted a beginner's aprpoach to to fix the anti-roll bars to soft at back and medium front, then just make one setting change per day on the dampers, depending on how slippy the track is. If the track is dry, I'll stiffen the dampers. As for tyre pressures, I'll measure them as soon as I come off track and keep them level all round at the recommended pressure when hot (which is around 28-30 PSI in the G40).
Other settings are best left to the experts, and for that you'll need to pay a team to do some set-up work on your car. I chose Ginetta specialists Fox Motorsports, and they will check through your car and set up the ride height (and corner weighting), cambers, toe-in, and show you how to do spanner checks for faults that develop in the harsh environment of a race track.
Corner weighting and ride height are the first things I would ask a specialist to set up on my car.
Driving a car on the race track will put big demands on all components. I always spend half a day checking over the car after a track day. As well as the spanner check, this also includes washing off any of the track debris and grime from under the car and in the engine bay. There's a lot to write about maintaining the G40, and I have a separate manual for that.
I also keep a record of the set-up changes that I make during track or post-track maintenance.
Media and Sponsorship
This is not everyone's bag, and I would only recommend taking it seriously if you're intending to make a career out of race-car driving. As an amateur newbie, you won't get sponsorship, except for help and possibly some small financial support from family or friends, or your own business. It won't cover a racing season at all, so you need to fund the car and the track days, plus race entries yourself. In the right championship, you can do this for a reasonable amount, affordable to your budget, such as the GRDC, Caterham Academy or 750 MC's Locost and Trophy series.