There have been many posts on this forum with regard to counters.
I have done a few myself.
Have you done a search for "counters"?
Have you downloaded the data sheet of a counter such as the 74LS93?
Have you done an internet search for "electronic counters"
Do you understand digital logic, ie. gates, Flip Flops, etc.?
I agree with your teacher. You will learn more if you do as much as possible yourself.
We can guide you, but you won't learn as much if we do it for you.