FreeCAD is an open-source parametric 3D modeler made primarily to design real-life objects of any size. Parametric modeling allows you to easily modify your design by going back into your model history and changing its parameters.
This software is most suitable for geometric designs, such as precise technical parts, replacement parts, gadgets, cases, scale models, etc. It’s less suited for creating organic objects such as figurines of humans, animals, or plants.
You can consult a resource of FreeCAD tutorials at here and download it here.