My Mac did updates daily, so I would have thought it would have updated IPhoto,
Your Mac will only update iPhoto automatically up to the last version that is compatible with your version of OS X. as long as you did not run Yosemite or El Capitan, it was not possible to update to iPhoto 9.6.1.
I have tried to find the iPhoto app in the store but it is not there, it is also not hidden either, I have tried every possibility and read what other people have commented on in the forums.
If you bought iPhoto with MacOS X 10.6 Snow Leopard or an earlier version, that came with installer DVDs, it is not an AppStore version and will not appear in the fourth tab "Purchases" and there is no chance to update it now.
But if your Mac came with MacOS X 10.7 Lion or a newer version, that does not have installer DVDs, iPhoto should be showing at the Mac AppStore for you.
Which version of MacOS X did your Mac come with?
Anyway, you need to find your iPhoto Library. By default your iPhoto Library will be in your Pictures folder and Photos for Mac will open it automatically. Is there an iPhoto Library in your Pictures folderol somewhere else on your Mac?
You may need to restore it from your backup, if it should be missing.