Here, visitors to our site can find tutorials on 3D Printing. For creating your own models, we typically recommend getting started with TinkerCAD to learn the basics of Computer Aided Design Software.
If you are interested in more advanced software, look into FreeCAD, OnShape, or Fusion 360. If you are looking for more modelling-type programs, such as for modelling characters or more organic shapes, check out Blender or Autodesk Maya.