how do I get the photo app on my mac. the old iphoto is now out of date with my software. It does not show up n the application update

To open your iPhoto Library in Photos, hold down the options key ⎇ while launching Photos. This will bring up a dialog to select a library. Select the iPhoto Library and then wait, while Photos is creating a new library from the iPhoto Library.

The new Photos app is built in to every Mac. It does not need to be installed and cannot be removed. Look for Photos in the Applications folder in Finder or the Launchpad on the Dock:



I had Photos create a new library from my iPhoto Library, however..... now it appears that there are 2 separate iPhoto libraries - it seems to have duplicated my old iPhoto Library and then converted it into an iPhoto library for Photos. Am I able to delete the old iPhoto library? Or will that also delete all of my old iPhoto library from Photos as well?

Photos does not duplicate iPhoto Libraries. That duplicate comes from somewhere else.

Open each library in turn to check their contents and to see if you want to retain them: Hold down the option (or alt) key and launch Photos. From the resulting menu select 'Choose Library'