MacBook Pro cursor won’t click

Try using a USB mouse. If the USB mouse works, then you have a defective trackpad and the laptop will need to be repaired.

If the USB mouse also does not work, then you may have a software issue or you may have some other type of hardware issue. Is the time being updated or is the time on the menubar frozen? If it is frozen, then you have some sort of GPU or display issue (most likely hardware, but still possibly software related). If the time on the menubar is updating properly, then you most likely have some sort of software issue. You can try reinstalling macOS over top of itself (shouldn't affect your data), or a more drastic approach is to perform a clean install of macOS or restoring from a backup (after first erasing the boot drive).

Make sure to have a good backup before erasing the drive for a clean install or restoring from a backup or you will lose all your data.

Please update us with the official Apple diagnosis so that it may help someone else in a similar situation.