This idea is pretty interesting, but I see a few problems with it.

1) Finding the right enclosure to fit an oscilloscope, let alone a decent one, is gonna be tough, and since you’re a beginner I’m guessing you don’t have access to drilling/painting tools.

2) I personally tried to build this exact kit and it was a little rough. I’ve got a few years experience in soldering and pedal building under my belt and even then I had trouble bc a single mistake could overthrow several hours of work.

3) Having experienced his kit firsthand, the visual aspect of plugging a guitar/synth into isn’t nearly as satisfying as you think, in fact, I mainly use mine as an audio probe for pedal troubleshooting. I could see it being a cool effect with a much more expensive, much bigger oscilloscope, but honestly this one isn’t worth it.

If you truly have your heart set on it, [here’s] (https://www.amazon.com/gp/product/B0728GCBLD/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1) a prebuilt model for a few dollars more that would save you many excruciating hours of soldering, although I still recommend you start a little slower. Try r/diypedals and maybe start with a kill switch or a transistor fuzz before jumping in headfirst.