If you are talking about the order of reaction in terms of the rate law you have to count all of the exponents in the rate law and that is the order of the reaction.
for example:
rate=k[A]⁰ would be a zero order reaction
rate=k[A] would be a first order reaction
rate=k[A]⁰[B] would also be a first order reaction
rate=k[A]² would be a second order reaction
rate=k[A][B] would also be a second order reaction
rate=K[A]³ would be a third order reaction
rate=k[A]²[B] would be a third order reaction as well
rate=k[A][B][C] would be a third order reaction as well
As you can in those examples to find the order of the reaction in terms of rate, all you need to do is add all of the exponents in the rate law formula.
I hope this helps. Let me know if you have any further questions or if you need anything to be clarified.