Need some help using the Photo app

Thank you. I do get that when I want to upload a photo, but that's basically the "all photos" album, so I have to scroll through every photo I have on the computer to find what I want. How can I navigate to a single, pre-existing album that I already have. For instance, if I have created an album called "vacation pictures," where can I find that album? I would have thought that after scrolling past All Photos, I'd see all the other albums, but that doesn't happen.

I administer three sites. If I use the share option, will it give me the option to choose which site I post as? I normally use the share option for my personal FB page, but haven't tried it for the other pages.

I also need to upload pictures to other sites, which would not show as a sharing option.

Think I have this figured out. FB will ask you to select which FB page you want to act on, so that's okay. On all other sites, the easiest way is to drag and drop the picture or pictures you want to the desktop. Then all you have to do is select desktop when the dialog box asks for the selection, and chose the picture/pictures on the desktop. When finished, you can just move those to the trash.