Awww, that’s sweet.
Really, it’s not as bad as it sounds. You just have to start with easy stuff. it’s possible to create some very nice 3D printed minis from free available stl files that have been printed before and been shown to work.
Go to Thingiverse.com and search for miniatures. There are literally thousands of free files. Most of them are geared toward gamers (monsters, fighters,etc) but there are still lots of non-gamer minis, and you can also shrink down larger items.
Check out Thingiverse - Digital Designs for Physical Objects. She has a bunch of cute things (little chairs and such), and you can download and play with those files to get a feel for things.
Oh, forgot to mention TinkerCAD. It’s free (web-based) and is one of the easiest programs to start with. @theroar84 has a ton of videos on it, and this article: Cardboard Cube Challenge - A TinkerCAD Skill Builder