I cannot find my photos in iPhoto, since the app is not support in this OS version, anyone can help?

You need to transition to Photos which replaced iPhoto 6 years ago.

Launch Photos with the option key held down. From the dialog, choose your iPhoto Library. Photos will create a new library from your iPhoto media, you iPhoto library will not be changed, though it will be renamed.

Hi there.

I've just found an old hard drive with the following - iPhoto is 'there' but not accessible. In info it says it has 1.2GB - I would kill to get access to the photos in this! Any hints? If I follow your advice above, it just shows the icon as greyed out, as per below, so there isn't a library to access. I checked 'Show package contents' and can't see a library.

Any help would be appreciated!

That's the Application. It contains no photographs. They're in the iPhoto Library which you would expect to find in the Pictures Folder.