Adding an asset (someone you want to monitor) is really easy in Control Centre!
First, select Assets from the left ribbon menu. Then make sure that nobody is highlighted blue by clicking them if they are.
Next, over in the right hand panel, select that they are a Person, put in their name, phone number and unique email address. You can also enter in any additional optional information you like. Click save at the bottom and you are done!
That person will automatically receive an email to set their password. Make sure to remind them to check their junk or spam folders if it hasn't shown up in 10 minutes or so.
This will also automatically create them as a User under that tab with the "Worker" permission. Head over to the Users tab to adjust their access level and other details.