Rote repetition and practice will get you in a good spot. Your (ie, our) reaction time might be slower than a 19 year old kid but racing lines and course layouts require knowledge and ability. So, just physiologically us older people would probably be worse at recovering a skid, evading crashes, or reacting to unpredictable drivers. Everything else is approachable with proper research and practice.
I've said it before, but just watch the top times and then move their braking points back 1 car length and just try to match that. That pace will plant you firmly in upper DR B. Then start gradually pushing deeper into corners with the least consequences. All the while, approach the game with the placid temperament of a Buckingham Palace guard as people ram, nudge, push, and slam into you periodically.