prrjim, yes a 3D printer can be very helpful in many ways but am glad you are coming to the realization that you will need a 3D model that can be cut in slices usually using a separate slicing program to do that sometimes supplied with the printer or you can get your own. The Ender3 printer seems to be a good buy. You can also download models that someone else made but then you are very limited and it might be cheaper if you wanted them you could buy them already printed. If you are serious about wanting to do this you will need to get a hold of some type of CAD software which you will have to learn how to make 3D models (not just prints). There is a learning curve but it can be done. Be aware that there is also a learning curve to use the 3D printer but not as much as the CAD part. I started building CAD models in 1987 on those big main frame computers and then went to the personal computer software. You are right, getting a printer and learning it's operation is the easy part.
I would recommend the Fusion 360 software which I believe you can still get free as a hobbyist but be prepared to spend many hours learning it and honing your skills by starting with simple parts and working up to the more complex.
https://www.autodesk.com/products/fusion-360/personal
I have Autodesk PowerShape software which I used in my job that I bought which would be overkill for what you want to do.
This is one of the latest models I printed also the building on the right.
I do not do model making or printing for anyone but Email me any time if I can answer a question
