[aK13]

You need to learn both to be good at either, but start with limit. NL will get you into bad habits (namely, you will likely become a weak-tight player), and good habits (like value betting) are much easier to learn at limit (and also you can think about situations mathematically, so it'll be a bit easier IMO). Both are good, both are profitable, play the one you like best once you've done both.