I have created a new album and have moved photos into it. However, how do I erase or delete that photo it if was moved there by mistake? If I use the 'delete from catalog' it also deleted the photo from the main media.
Do you mean catalog when you refer to album which is what the other poster is assuming.
If you actually mean Album in the true sense and what to remove a photo from that album then right click on the photo and select Remove from album. It will give you a list of albums which contain that photo so that you can select the album you want to remove the photo from.
If we haven't answered your query, please let us know which version of PSE you are using.