I would agree with all of the above. While learning how to effectively use the camera - shutter speeds, aperture, ISO, etc, to creatively control depth of field, blur, etc., - is vital, it's also true to better equipment will yield better results - they aren't mutually exclusive.

50mm isn't a very good landscape lens. While I have one in my bag, I very rarely use it. My 10-22 and 24-105 are by far my most used lenses for landscapes. 18 should be fine to get started - and the 55 will let you feel how wide it actually is. I'm not as familiar with the Nikon lens lineup, but I'm sure they have something in the 15-20 to 60-90 zoom range that would probably be the best option.

While primes do have an advantage at the extreme in image quality, the flexibility of zooms more than trumps that advantage to me. Unless you're in a studio, or another situation with known parameters, I'd say zooms is the way to go.