Hi Jenny
You are not duplicating the photo. You can have the same photo in as many albums as you like, it’s just an organisational tool. Likewise if you delete an album you won’t delete the photos contained they will still be in the main library.
You can do a test to help you feel comfortable. Click on the ‘My Albums’ folder on left. Right click and choose ‘New Album’, no need to even name it, although you can if you like!
Then go to the very last photo at the bottom of your library and drag it into the album. The
folder symbol will change to very small thumbnail of that picture.
Click on the album to enter, you should see the picture. To delete picture from album right click on the picture (In the Album) and choose ‘Remove from Album’ at the bottom of the menu.
The album will now be empty but if you navigate back to the main photo library it should be still there.
Drag the photo back to the album and then delete the album. To delete the album, right click on the album and choose ‘Delete Album’ a message will appear. Click delete. Then check in the main library the photo will still be there.
If you accidentally click on 'Delete photo' instead of remove photo, not a problem as it will be in the 'Recently Deleted' folder top left. You won't have lost it.
Hope this helps