What does it mean to be a Youtuber?

It's simple. If you make a decision to continually release Youtube videos, then you are a Youtuber. You may not make any money or have any subscribers, but if you stay persistent and release those videos, then that's all it takes. Quality doesn't really matter (as evidenced by most Youtube videos, but it greatly helps when you're getting started), but a steady schedule of 1-3 videos a day is all you need.

The rest is just a waiting game, the more you work it, the more people will watch. Momentum will probably start off very slow, but as you get more views and subscribers, it'll accelerate.

(Also, if you go out your way to become a Youtube partner and add monetization, then that only shows a more serious individual. I would recommend doing that if you spend any bit of time making your videos, as you wouldn't goto work and not expect a paycheck. For me, it takes about 3-ish hours per video, sometimes more, and some of them much less.)

Right now, I'm still testing the waters, and have flexibility to change up what I'm doing. You kind of have to just release a wide variety of videos and see what "sticks", then drop the stuff that doesn't do well. Not a good strategy for a tech company, but perfect for a Youtuber just getting started.