Recommendation for free, intuitive offline 3D modeling software for 3D printing
I suspect there may be fewer answers than we expect.
Personally free software wise I like FreeCAD but it is not similar to the simple shapes of tinkercad at all and not intuitive.
I did know someone who used something from https://www.xyzprinting.com that was very similar to the tinkercad stuff, but eventually ran into limitations and switched to more advanced software anyway.