At the top of this page you will see a pale grey bar across the screen with nine options (starting with Settings) and a Search box. Click the word "Albums" with the camera logo alongside it and it will open a page headed "My Photos". One of the choices is to "Create a Photo Album". Click on this then follow the screen instructions to Browse your PC for the photos you want to show and upload them to your new album.
To add a photo to a post simply click on the camera icon just above this dialog box ("Insert Image from Album"
and select the album and photo you want to add.
Even I can do it, so it can't be complicated!
Dave M