How to pause iCloud uploads on MacBook without losing files?

Yesterday I started a 1.4 TB files upload to my iCloud storage from my Macbook's desktop. The files are no longer on my desktop but in iCloud and are currently uploading. I'll need the files to be completely uploaded within a couple days but at the rate they are uploading this isn't going to be enough time. My questions are: How can I pause the uploading and be able to shut down my Mac and if I can, where will the files that didn't get uploaded be? My main concern is that I don't want to lose any of the files that haven't uploaded yet. There are hundreds of them and I should have done a little at a time. Please help.

[Re-Titled by Moderator]