Hi Alana, Welcome Back !
As Bill stated you have to "reserve" your copy of Win10 before it can be installed on your computer.
There really is no need to disable all Windows Updates as the "critical" category relates to your computers security.
What happens is ... that during a recent Windows Update cycle a white Windows icon appeared in the "notification areas" in the lower right of the screen:
(click on the picture for a larger image)
Clicking on the white icon opens this display:
(click on the picture for a larger image)
Windows 10 really is optional.
If you DON'T want the upgrade, DON'T click the "reserve" button in the red square shown in the picture above.