Honestly, it'd be great to learn RWD young. I bought my miata when I was young, I was responsible with it, learned the techniques associated with an RWD car at its limits by autocrossing, practicing in the snow, rain, everything I could. I'd definitely recommend doing the same.

As far as actual car choice, E30s are friggin sweet platforms, and they're available at really affordable prices well within the kids price range. Same goes for miatas...if you're comfortable with yer seckzuality . They both get great gas milage, they're pretty durn safe (if you get one with airbags) and require little in terms of modding to make them considerably more fun than stock. Most importantly, they've got SOUL *****.