There's probably an easier way to put "two pictures in the same frame", but this is how I'm doing it till I learn the shortcuts. (I'm using the "big" version of Photoshop, but I'm told you can do this in Elements too.)
Select your pix and open them in Photoshop.
But if they need to be cropped ... start by cropping one of the photos (using the "box" icon - the Crop tool - near the top of the toolbar, which is at the left side of my screen) -
Now the fun starts. Still using the "box" resizing tool (the Crop tool), select the entire image. Then use the small box halfway up the dotted line on one side of your photo to draw the cropping box outward on the side where you want to put the other photo. I make this box bigger than needed, as it can be cropped later.
To be able to drag the second photo into the white area, you must select the arrow in the menu bar - it's at top left on my screen. Then move the other photo into place (and either close the small window or drag it back where you got it from) -