How do I retrieve the iPhoto pics?

iPhoto was discontinued 5 years ago. It is no longer developed or sold. It was replaced by the more powerful (and free) Photos.app that comes with the OS. You can migrate to that app very simply:

Hold down the option (or alt) key and launch Photos. From the resulting menu select 'Choose Library' and point at your iPhoto Library. It will do the rest.

If you prefer not to use Photos there are several 3rd party apps that you can use. Which to choose depends on the kind of photographer you are and your budget.

Which system version are you running?

As pointed out before, the most recently used iPhoto Library should have been automatically converted to a Photos Library, when you first launch Photos. But it will not happen, if your iPhoto Library is in a location, that is not compatible with Photos. If you are keeping your iPhoto Library on your system volume, it should be in your Home folder, not in a shared folder. If it is on an external disk, the disk should have a wired connection, must not have been used for Time Machine. backups, and the file system format should be MacOS Extended(Journaled) or APFS. Move your Photos library to save space on your Mac - Apple Support

The iPhoto library should be automatically migrated to the Photos app the first time you open it.

iPhoto is obsolete.