For primarily functional parts like that I'd recommend the Prusa Mini. That's exactly the position I was in a few years ago, and to be honest I just jumped in,

For primarily functional parts like that I'd recommend the Prusa Mini. That's exactly the position I was in a few years ago, and to be honest I just jumped in, Fusion360 (for example) is pretty accessible if you have an engineering mindset at least. Clough42 has some great design through to printing videos on YouTube. I think I'd seen some of those, and then had a go at designing something I wanted, (which was easy enough and looked good 'on paper') and then ordered my Mini.