Two cycle mixing oil should be used and most likely the mixing ratio will be 32 to 1. The other common mixture is 50 to 1 but if in doubt at least make 40 to one as will still run.
It depends on the blower. If it is a 4 cycle it does'nt take mix. Most blowers today are 4 cycles. The older 2 cycle blowers do need mix. Manufacturers now offer 2-cycle oil in 2. 6 oz. containers for easy mixing. Add 1 gallon gasoline to get desired 50:1 ratio.