Menu system and Turtle
Why are you using a global? There seems to be no need for it, and in general it's something to avoid.
Why not factor out the common stuff? In your main loop you have a bunch of if cases which all start in the same way and then all call methods which are very similar. If you start by checking that it's a valid input you could pull out the calls to how_many() and start_point() and even the loop for a in range(howmanyof):.