ok open photos (the flower thing)
1 File -new empty album you will get a chance to name it
2 highlight the photo you want to move and then click the + sign you will get a drop down that says “add photo” or “add xxx photos” and one of the drop down options will be album. Click on this and you will see all the albums choose the one you want to put it in. Rinse and repeat :) I know this works cos I just did it.
The photo you have moved will still show up in “all photos”, also last import, recently deleted and any other system albums. The computer doesn’t actually move the photo anywhere, it just adds a tag to it saying where it should show. This means you can add the same photo to several albums without the computer needing to have several copies.