Requirements for microcontroller programming of an RFID project
I regard this as a too serious project for a beginner, since you're meddling with something that needs reliable operation - with little experience you might leave critical bugs in your code which would leave you with a mild annoyance at best or a damaged vehicle at worst.

To answer your original question:

You could program it in a high level language, however that would defeat the purpose of a microcontroller, because you'd be using it's resources very wastefully. If you really want a high level language, you can just plop a Raspberry Pi, or a Carambola2 unit in there.

If you desperately want to go for a high level language, you could go for an Espruino, however javascript is quite similar to C/C++, so why not just go for the true way of coding microcontrollers immediately?

I'd recommend trying an Arduino, since it'd have all the modules you'd need easily available as well as a rich array of drivers/libraries already written for said modules. This would mean that you would have to study the C language a bit, however it's nothing too difficult if you need just a simple application to recognise a specific hex stream from an RFID reader and switch output pins accordingly.