I use FreeCAD for most of my stuff now, but I found it very, very hard until I watched some video tutorials. After a little training, I’m really happy with it. I tried OpenSCAD, and that can be a really good option depending on your background.

You will also need to choose a slicer, or try some different ones. A lot of people like the prusa slicer, but I’ve never tried it. I started with the cura slicer, and it worked well enough that I haven’t tried anything else. It seems that some people really like the new orca slicer, so that might be a good choice too.

If you can connect a computer to your printer (either raspi, or something else), some software to manage that is definitely helpful. Octoprint is the most popular option, and maybe the only one; so look that up if it’s something you think would be relevant for you. There is also something called Klipper for upgrading your printer’s firmware. Whether or not that’s for a “beginner” depends very much on what their background is, but it’s something to consider if the additional features sound worthwhile.

I don’t know if these are really the kinds of resource suggestions you had in mind though.