I feel like I have been driving and following sign posts until I come to a T junction and there are no more signs. The tutorials are good for telling you what and how you can do something to a photo but how do you get that photo into PS to start with?
Photoshop is the same as every other computer application in this respect. You simply open the photo file in Photoshop. If you don't know what this means, you need computer lessons, not Photoshop lessons.