how can I see my iCloud saved photos from my MacBook

If you have iCloud Photos turned on, the photos on the Mac are the same as on iCloud, with the possible exception that some of them may be space-saving optimized versions if you have that option turned on. You can also use an internet browser and login to icloud.com and go to the Photos app there. See: Set up and use iCloud Photos - Apple Support

If you didn't have iCloud Photos turned on but do have an iCloud backup of an iPhone or iPad, you can restore the entire phone or iPad (not just the photos) from iCloud but you cannot otherwise view the contents of the backup. Restore or set up your device from an iCloud backup - Apple Support