I learned on a chain driven BMW F650 classic and would highly recommend any BMW F bike as a great beginner bike. The riding position, torque and wheel rake make for a very forgiving motorcycle. In 1997 they made an ST version that was more street oriented than many other F650 models. Some F bikes were modified with lowering kits that may or may not make for a better fit. Check out www.f650.com for very supportive owners forum. I chose the F650 because I did not care for the riding position of either the cruiser or sport bikes. Good luck choosing your first bike. There are a lot of great choices out there.
Frank