I'm new to DIY pedals, and I wanted to know about some... theory stuff.

I made the following schematics in LTSpice:

It's the "Hornet" - Fuzz... here is the original:

Now if I simulate that circuit, I get this output signal:

Am I doin' it right?
I don't really know what "distortion" would look like, or if it even should be visible in the voltage... I could also make a FFT, but it looks quite... messy.

Also, the amplitude is quite a lot higher than the original signal... normal?

I hope the right answers will enlighten this topic for me!
I'm not an expert on the subject, but from what I do know, I believe you may be right. The fuzz does produce a "square wave"- the choppy structure is what makes the gritty distorted sound. And the amplitude being larger is probably a result of increased signal volume as a result of increased gain.