My MacBook Pro screen freezes at Photos. The cursor moves but no response from any button.

Hi - Try restarting your mac in safe mode and then trying.

Then restart normally, and try again.

Safe mode will clear temporary files and caches, and sometimes fixes odd glitches such as this.

Start up your Mac in safe mode – Apple Support (UK)

If Safe Mode doesn't fix the problem as a test launch Photos with the Option key held down and create a new, test library.  Import some photos and test to see if the same problem persists. Does it? This tells us if the problem is limited to your current library or is more wide spread. If the problem is gone in the test library try to open your current library again.