Enemy shot

Hey guys I having problem with the shooting my Enemy started to make a lot a shoots
The reason is I am using (function update) the the shoot occurs every frame.
I try the tutorial of the tornado twins on YouTube but I did work.
How I can make my enemy shoot one second at time?

Try InvokeRepeating(“You Function”, 0, 1)

0 being first call in seconds,
1 being repeat rate in seconds