It's great to see you here today, @wambua.
The Time tracking only user type lets you invite employees or vendors to enter their own timesheets. They can only view timesheets and reports in QuickBooks Online (QBO). It doesn't count toward your user limit since it's a non-billable type.
Please take note that you're unable to add a vendor as a time tracking user if their 1099 tracking is turned on. Although, you can add them as a new vendor with a different email address. You can also manually enter timesheets for them. For more details, check out this article: User Types In QBO. Then, go to the Time tracking only user section under Types of non-billable users.
When you're ready, you can add your employee or vendor as a Time tracking only user. I've attached a screenshot below on how it looks like in QBO.
To help you set up timesheets in the program, I recommend visiting this article: Timesheets Overview. It also provides you steps on how to enter, approve, print, and troubleshoot saving timesheets.
Also, I'd suggest going to the Manage users page from Accounts and Settings. From there, you can edit the user access rights, view their activities, and delete them.
I'm here anytime you have other concerns. Enjoy the rest of your day, @wambua.