How do I mask a shape (rectangle tool)?

[VitoEmmanuel]

I feel like this should be really simple, but somehow I am unable to get the desired result. 
 

I have a photo that I want to add a border to. The border looks like a bland picture frame, just a square going around the image. Later I plan to mask this border frame to make it look like some of the image is poking out of the picture. My problem is that I can’t make a simple mask in a shape. How do I drag a smaller square onto a larger square to make the center of the larger square transparent?

thank you in advance. 

[VitoEmmanuel]

How do I make that black square transparent, so that the images behind it can be seen?  Hope that clears up any confusion. 
im just trying to get a teal frame/border.  

[v_kyr]

As the layers are actually arranged, hiding the inner black one, or changing its blendmode transparency, should make the covered green area to appear. When the green and black squares are combined (or their layers merged into one), then a rectangular selection of the black part and a delete of it would let the layer below these appear.

What you are going to do when it's final, is also known as an "Out of Bounds" or "Pop out" image then.

[Cecil]

11 hours ago, VitoEmmanuel said:

I feel like this should be really simple, but somehow I am unable to get the desired result. 
 

I have a photo that I want to add a border to. The border looks like a bland picture frame, just a square going around the image. Later I plan to mask this border frame to make it look like some of the image is poking out of the picture. My problem is that I can’t make a simple mask in a shape. How do I drag a smaller square onto a larger square to make the center of the larger square transparent?

thank you in advance. 

I hope this helps you.    

 

[DM1]

If you just want to make a a simple frame...

Draw a rectangle and fill with frame colour. Draw a second rectangle and fill with black. (Fills are optional, just makes it easier to see and size).  Resize and position the second rectangle over the first to create the desired frame size. Note the smaller rectangle layer needs to be above the larger rectangle layer. Select both layers. In the Edit menu tap Geometry and select Subtract. Now you have a frame with nothing inside it.