Optimize my mac

Uforia wrote:

What does this mean and how do I do it?

You have not provided any details or context. Maybe you are referring to this:

Optimize storage space on your Mac - Apple Support

If you're referring to the little alert-like tip at upper right you get with a new user, it just means the Mac is setting itself up for that user, i.e. the defaults are being utilized.

If something else, details are insufficient.