I now own the game Super Mario Maker 2, which relies heavily on the touch screen. The touchscreen pen that you get to the limited edition is in my opinion not for build.
So I wanted to ask if I could use my 3ds pen without crashing my Nintendo Switch or adding any other damage.
No, because the switch's display does not respond to pressure.
But you can use a pen like this:
The switch screen reacts like any smartphone only with skin or something similar soft.