I started out using Sketchup. It is still a great program, but no longer has an un-timed license available. I purchased the last un-timed license (Sketchup 2020 for almost $1,000) and use that program when I need a quick and dirty 3d print. Sketchup 2016 can be downloaded, allows for free use, and still works on Monterey, and with a free plugin that translates to STL you can do a lot of at home builds.
FreeCAD is at 0.20. It is a tool that has a lot of the look and feel of Solid Works. With a lot of YouTube tutorial videos, you can come up to speed with it quickly enough. It probably takes 4 or 5 times as long to crank out a design with FreeCAD as Sketchup, and probably 10 times longer to do it on Solid Works. SW takes so long because that program is so bloated it almost requires a disk access every time you move your mouse. (That is only a slight exaggeration.)
It took about 2 days, but I was finally able to get a 3d box printed from FreeCAD. Not too bad, as that included the learning curve. Measurements for an item are called constraints. FreeCAD lets you know when you have all the measurements entered (fully constrained). 3D objects alway start out as 2D objects (called sketches) and these flat items are padded (extruded) into a 3d area.