Welcome to the Board! Singer 66s are great machines. You will need a base for it, as it rests on moving parts at the bobbin end without a base. I make bases out of 1"x6" board ripped in half, 6 pieces of wood total, it requires some router work (e.g. for the hinge pin fittings on the back side). Frankly, for the work you're talking about I would want a wider footprint on the base, from front to back.
If you're going to be working on canvas, I'm wondering about the belt on the motor in the picture. I recently cleaned up a machine and with a cogged belt it would not spin up all the way, but with a v-belt it would. You should get a proper Singer belt for this machine. You can test all of this after you service the machine.