comments, commence

Comments or comments is the plural ( more than one ) of "comment", meaning a short remark or observation--
There will be time for comments after the lecture.
The critic's comments were more interesting than the film.

Comments or comments is also the third person singular ( he, she, it ) form of "comment", meaning to offer a short remark or observation--
He comments on every photo she posts.
The party hasn't begun until she comments on every outfit.

Commence or commence means to begin or start--
We're here for a meeting. Let's commence.
The baby's pout means he may soon commence to cry.

Now that you know that, you can say--
"We've heard enough comments, let's commence voting."

Note--"commencement" means a start or beginning--
At the commencement of the exercise, everyone should be lined up, single file.
"Commencement" also means the graduation ceremony at which diplomas are awarded--
Make sure you wear your cap and gown to the commencement ceremony.
Not to be confused with "comments meant", meaning what the short remarks or observations ( comments ) intended to express or indicate ( meant )--
He tends to be obscure; I still don't know what his comments meant.