Where can I get a free blood sugar monitor?

Your doctor . Very often, doctors' offices carry glucometers to give patients. Certainly, a local diabetes center or diabetologist's office would carry these meters. The companies making the glucometers get their money from selling the glucometer strips so it behooves them to leave glucometers in physician offices.
Check w/ your doctor. Sometimes, meter companies give meters to doctors' offices or pharmacies, knowing that once you have a particular meter, you're likely to buy strips for that meter for a long time. Check w/ your doc or pharmacy. Other companies off rebates after you pay for a meter for the same reason. Most meters, though, can be bought for $20-25.
Health Fairs, Events. Try your local hospitals and ask about schedule for health fairs and screenings, this is a good first try. remember Walmart has an inexpensive meter, and the strips are only 9$ for a pack of 50!