There are lots of sentences you can make with effortlessly. Like...

I effortlessly answered that question.

Bob effortlessly ate a pie.

She jumped over the pole effortlessly.

And there are many many many more sentences you can mark with effortlessly.

What does the word effortlessly mean

Commencement actually is formed with a root word "commence" and a suffix "-ment". There is no prefix.

The dog sailed effortlessly over the fence; and was gone in an instant.

Our team seemed to win the match effortlessly.

the performance will commence at 8 pm sharp