Amber, do you want the deck as low as possible? could 8 inches in height from the concrete be OK?
If 8 inches is OK, then use Dek Blocks sold and found at Home Depot or any home center. They are formed footings for 4x4 or 2x's to fit into. They are made for this purpose and others.
You can also build your deck as a platform right on the concrete. The weight of the lumber will not require any tieing in to the concrete. If you use this method, be sure to use Treated Wood. this method would be not as high as the other option as you would not use beams or joists. I would suggest placing 4x4's the width of the concrete and every 16 inches apart then fasten your 2x6's to that. Go around the perimeter of the platform and tie the 4x4's all together. This height will be about 5 inches. This is as low as you can go.