No Utilities tab in photos - Macbook air!

leonore96 wrote: … I was told to use the Utilities function to retrieve the lost album

I'm sorry that you were told that. The Utilities section was added in Sequoia as a place to hold some of the views you see at the top of your Sonoma Sidebar, like Duplicate, Imports, and Recently Deleted. Those things are just in a different place in Sonoma.

Recently Deleted is a view that shows pictures that were deleted within the last 30 days, and it gives you this time to change your mind. But Albums aren't pictures, and albums that you delete are not included in Recently Deleted.

The thing is, pictures aren't really in an album. An Album is a list of pictures that you would like to see together, kind of like a playlist is a list of songs. That's why you can have a picture in several albums without taking up any more storage. An Album is just a list. So, as the little blurb says when you delete an album, no pictures are deleted when an Album is deleted-- just the list of what was in there. You can't undo that. But all the pictures are still in your Library, and you can "put them in" a new Album (meaning put them together on a new list.) One way is to go to the Library, select the pictures that you want in the Library, and then choose the menu item File> New Album from Selection. Or you can make a new album and drag pictures to it.

To recover albums you would need to restore your Photos Library from a backup, that you made, while you still had the album. Do you have a recent Time Machine backup of your Mac?

But restoring a previous version of your Photos Library will take it back in time. You will need to keep the new library as well, so you will not lose the photos you imported after you made the backup, and and have to recreate the most recent adjustments. It might be less trouble to recreate the missing album, as Richard suggested.