Hi there. I’m something of a 3D printing veteran, I’ve built a dozen printers, had a side gig maintaining printers for a small manufacturer, done all kinds of crazy crap with 3D printing.
I see from other comments you have an Ender 3 Pro. Decent little machine, should be lots of fun.
The biggest advice I can give you is: Watch the thing print. You can learn so much just by watching the thing print. Especially if something is going wrong. Sit there and watch it like television. It will give you this great sense for how the printer works. It’s not a Star Trek replicator, physics is happening while the part is halfway done. Heat, inertia, gravity, they’re all factors.
Download stuff from Thingiverse to print out. There’s lots of godawful models out there written by people who don’t have a clue what they’re doing. They’re extremely instructive. I found a cool little low poly skull that was modeled tilted at a slight angle to the axes, so the bottom layer was at a very slight angle to the bed and it tried to print the thing uphill. Print stuff out, watch it fail. Learn.
As for a tech stack: I’m a Linux guy myself. My current favorite workload is FreeCAD and Slic3r.
FreeCAD is very powerful, if a bit clunky. The UI is written in Python, and it leaks into the user experience a bit. Start using the parametric features, especially referring to the built-in spreadsheet in your sketches, and you’ll start to recognize it. I’ve also used Fusion360 and OnShape at various points in my career, and learned things from both, but I do all my 3D design work in FreeCAD now.
Most slicer software works on Linux, even Simplify3D does. I’ve used many of them over the years, and they all do a pretty good job. Try several out, you’ll find most of them in your distro’s package manager.
One thing I would suggest: Learn a little bit of G-code. Reasons why: It’s useful when diagnosing problems with the machine, and it can be handy to customize the start of print and end of print routines. Like when you start a print, and it heats up the bed, then it heats up the nozzle, then it homes the axes, and maybe ejects a little filament to clear the nozzle…that’s all G-code that the slicer software appends to the .gcode file. Usually there’s a text field somewhere in the settings that lets you alter it.