I keep getting the spinning Beach ball in Photos on MacBook Pro 17 with macOS 10.13

Could you give us some more background information?

• How much free storage do you have? If you are having less then 20GB of free storage, try to free storage.
• What are you right-clicking, when this happens? An album? A folder? An Image? A video? Or multiple selected items?
• And where is your Photos Library stored? Is it in your Pictures folder in your Home folder or have you moved it to an external volume? If you moved the library to an external drive, check, if the drives meets the conditions described here: Move your Photos library to save space on your Mac - Apple Support
• Are you using iCloud Photos? If yes, check your internet connection and if something (Antivirus filter or Firewall) could be blocking the access to Apple's servers.
• What has changed, directly before the problem first occurred? If you recently installed some third party software, test in safe mode, if some third-party software is interfering: https://support.apple.com/en-gb/guide/mac-help/mh21245/mac Safe mode will clean some caches and disable third-party system additions,

Try to narrow down the problem with systematic testing:

• Find out, if the beach ball only occurs for certain items. There may be corrupted media in your library or ver large files, or files with unsupported filenames.
• Find out, if you are having the same problem with a different Photos Library, just created for testing.
• Find out, if there is a problem with your user account by testing in a different user account, for example the guest user or if the problem is system wide.