There is no faster way to learn where the limit is than a kart, because it tells you the truth instantly and cheaply.
No electronics to hide behind. Braking points, apex, throttle on exit — a kart rewards precision and punishes greed in the same corner. Champions came up this way for a reason.
Rental karts, no ownership, pure practice.
Cheap grids and real, wheel-to-wheel racecraft.
Whatever you drive, read the safety basics first.