Firstly, I would recommend that you learn all the exponent laws :)
For this question, we will actually be using one of these laws!
This law can be only used when two or more numbers/ variables with exponents are multiplied together.
Simply add the exponents together to simplify.
In this case:
p x p²= p³
(the exponents 1 and 2 add to 3)
Hope this helps!
Feel free to message me if you have any questions :)