Spinning is a high cadence - 90 rpm or more... and thats what people recommend

However, I find spinning hard work and at best I can get to about 92

In a TT I ride at about 86-90rpm, in training I pedal anywhere between 70-85rpm

Just experiment with it... my heart rate rises as my cadence gets up to 90 - so I am actually more efficient at a lower cadence...

Good luck