Nitro is fun, but it's also messy, requires a lot more maintenance, and tuning the engine can be finicky. I'd recommend electric for a first car. If you haven't driven an RC car before, a stock-ish motor will be plenty fast and fun until you get some "seat time."damn i have been missing out here! i've been really wanting to get into RC cars for a while... i love motor driven ones and how they sound, but the electric brushless ones are also nice.
Cant decide what scale i want to get or where to start though. it can be quite a rabbit hole. and i don't really have anywhere to run them
RTR will get you going quickly and I was surprised at the quality of the $200 RTR "drift car" my kid got for Christmas. However, building from a kit is fun if you like a project. I think you'll better understand how to fix, maintain and upgrade the car if you put it together from a box of parts.