I can no longer access any of my photos on Photo. All I get is the tutorial about what's new with Photo.

That would indicate that Photos has lost track of your photo library and has created a new empty library. You need to track down (or restore) your previous Photos library and switch back to using it.

As a first step, go to the Preferences panel in Photos, select the General option, and copy down the information next to "Library Location:". Now quit the Photos application, then re-launch it while holding down the option key. This should give you a list of all the libraries visible to Photos.

Best case, you will see your previous library there (usually in the Pictures folder in your user storage area, usually named Photos Library.photoslibrary) and one newer library with the name you noted above. Select the previous library and see if your photos are now visible.

If you see more than two libraries in the list, you may need to repeat the process until you find the one with your photos.

If you see only one library and it does not contain your photos, or if you see no library at all, come back and tell us more about what you were doing before you lost track of your library.

What system and Photos versions are you using? Or are you using iPhoto? It's not clear which one.

Which iPhoto version?