Do one of the following:
Create an empty album: Choose File > New Album, or hold the pointer over the sidebar next to Albums and click Select the photos you want to add, then do one of the following:
Drag the selected photos to an album in the sidebar.
Control-click one of the selected photos and choose Add To > [album name].
Tip: To add photos to an existing album from a folder in the Finder on your Mac.
Click Albums in the sidebar, then do any of the following:
Rename albums: Control-click an album, choose Rename Album, then type a name for the album.
Duplicate albums: Control-click an album, then choose Duplicate Album.
Merge albums: Drag an album into another album.
Order albums by date: Choose View > Sort, then choose By Oldest First or By Newest First.
Rearrange albums manually: Drag the albums into the order you want.
Order albums alphabetically by title: Choose View > Sort > By Name.
Go to the Photos app Create Smart Albums to group photos and videos automatically on MacPhotos settings on Mac