Hi
Finally found my plans for the Viggen. On the 1/10th size the CG is placed 100 mm (4 in) behind the leading edge of the main wing where it enters the fuselage. This is a safe starting point for balance.
Otherwise, the most valuable tip on setting up controls, be very careful with the aileron throw. Use MAXIMUM +/- 5mm ( and some expo for my liking).
Use +/- 20 mm for elevator throw.
For first flight, do not use canards, you can experiment with them later, most people here never use them, as they have very little effect, but complicates flying the model.
Good luck!!