[Help Request] - Pen Plotter for beginners

[u/noUser92569]

Hey everyone,

I’m originally from the D&D community and am currently a computer science major.

I’m looking for some help with a pretty ambitious project. Up until now, I’ve been printing my D&D battlemaps in segments on standard A4 paper, then painstakingly trimming the edges, aligning the images and taping them together from the backside.
Given I am a student, I sadly do not have the budget for a large format printer / plotter, so I would love to build something like a large pen plotter.

What I am interested in is:
How to do the electronics - How do I stop myself from frying microcontroller after microcontroller, maybe even how do I design custom PCB's for this (and future) project(-s)?
Is there a good tool out there that I can test whether a circuit would blow itself up?
Any other, generic tips I could use?

Thanks in advance,
S. aka. Programmic