Question

Implementing the changes to our menu, should be our first priority. Is this sentence grammatically correct?

Answer 1

Im 99% sure that is correct as long as you understand the definition of the word implementing you should be able to answer this question. So if i were you i would look in a dictionary for the definiton then decide if it is. 

Answer 2

I don't actually believe the coma should be there, I don't know if I'm correct but a pause there seems awkward and unnecessary.