The speed of reactant forming a product

is that what rate of reaction

No, the speed of reactant forming a product is the rate at which the reaction is occurring. The rate of reaction is a measure of how quickly reactants are being converted into products or how quickly the concentration of a reactant or product is changing with time.

Yes, the speed at which a reactant is converted into a product is indeed the rate of reaction. The rate of reaction is usually expressed as the change in concentration of a reactant or product over time. It indicates how quickly the reaction is occurring.