Like learning piano, modeling demands that you start with simple things. Do the absolute easiest things on your coffee table or in your house. Cups, vases, plates and then speakers, T.V.'s  Chairs, tables and then an entire room. Keep doing simple things and you'll run into problems that you will need to learn to solve and this will help you master the toolset/ Once it becomes second nature to you, then you can start working on a technique. You can create any model starting with a single straight polyline and rough out the forms and work in details as you go. Google up some images of a wrought Iron fence or a plant and just keep solving the "how do I do that"? puzzles and pretty soon you'll be making whatever you like.