I don't understand how to use pen tool at all.
I see people using it all the time, but i don't understand how they use the pen tool.
Everytime it makes the lines fine, but it fill them in with or whatever my second material color is.
Am i doing something wrong or am i just confused?

I always just make the second color transparent so that there is no fill. Just press the little O with the slash through it under the color in your palette. I don't have X2, but I'm assuming it's the same.

Nope that O with a slash through it isn't there, at least I can't find one.

Try right-clicking the vector object once it's made and go to properties. There should be an option somewhere that that "No Fill" or something along the lines of that.

Wait, sorry. I thought this was for PS. My bad.