Well Ninjutsu is any technique that uses chakra.
It can mainpulated with Shape Transformation and Naturo Manipulation.
Non-Elemental Ninjutsu is techs like Kage Bunshin and Shadow Shuriken and can be very effective if used intelligently.
Well I was looking for a key phrase: pure chakra. Basic ninjutsu utilizes pure chakra, with no sort of affinity. As opposed to elemental chakra, pure chakra can also come in many different forms, from shadow clones to Rasengan. This is very important, as it's very unlike elemental ninjutsu. For example, for fire ninjutsu, there aren't many variations, just different things that the fire that you spit out do. Pure Ninjutsu has perhaps the widest range of possibility.
So let us begin. First, I want you to meditate. Focus your chakra, get it flowing throughout your body, and then we'll get to the good stuff.