User Activity

Using TR8520 on a W10 HP.  Trying to print 4 iomages on a single sheet  of 4 x 6 glossy paper. There are 12 images in file but printer app only allows a choice of 5 of them.  How do I get the app to allow me all of the images?
Trying to set up my tr8520 printer in wireless operation.  In the instructions I'm asked for a "pass/phrase.:  Not sure what that is, never heard it before.  If its password, how do I set it?