Photos

No. The iCloud Library is just a syncing service not an off computer storage facility. Any changes you make to the local library, deletions, additions or edits, will be duplicated in the iCloud library.

You can save quite a lot of storage, if you enable "Optimise Mac Storage" in the Photos > Preferences > iCloud. If you do that, Photos will automatically remove some of the big resolution original image files, if storage is needed for other applications. It is fully automatic, and the size of the library can shrink over time down to 10% of the original size. But do not delete any photos that you want to keep.

TGTIA:

It does depend upon what you actually did when you say you "uploaded all my photos on my MacBook Pro to my iCloud storage."

If the photos are managed by the Photos App, then, what Old Toad and léonie have written are all, completely, correct.

If, on the other hand, you did something else, then other "rules" may apply.