do you mean track days, ie your road car on the track but offically not racing anyone or timing yourself (you'd get chucked out for it), or full on racing in a non road car trailored to events etc etc
The former is great fun and probably a good way to see if you want to progress to racing. Full on racing is ferkin expensive, even the entry fees can be a few hundred ££ plus the championship fee, then you need a competitve car built to MSA regulations. Throw in a triple layer nomex suit £300+, decent helmet, boots gloves etc and just kitting yourself out wont see much change from a grand.
How about getting into sprinting or hillclimbing in the road classes? A lot take place on real circuits like croft or knockhill, its against the clock and you up against other class competitors to set the fastest time around 1 or 2 laps from a standing start. Some venues are stately homes where you blat at full chat down the estate road, often with spectators watching etc. Its proper motorsport!.
All you need is the basic personal gear, cheap helmet, proban suit £100. Mods to the car in the road classes are strictly controlled. You can change your front seats but the rest much remain as standard. No perspex windows or trim removal (other than carpets). No need for a cage etc. make your own timing strut (to trip the timing beam) and cover the neg terminal on your battery with yellow tape and your away. You can modify the car, engine wise etc within limits.
You do need to join an MSA recognised club £15 and apply for an MSA non race national B license £39 and no courses to take and you could be there on the start line in no time. Heres a pic of me on the sprint at Teeside Autrodrome on good friday starting to get sideways over a crest. (there again on 5 may bank holiday monday)