I'd consider Illustrator instead. It's vector based, it's great for layout, and boxes are
boxes, not a set of pixels are are coincidentally shaped like a rectangle (admittedly, Photoshop is also capable of this, but it's much more limited). It's also intuitive - you move things by clicking on them and dragging them. Pretty much all of the things it seems that you'd like to do would be possible and easy to do in Illustrator. As you said, you're not interested in photo editing.
If you do decide to stick with Photoshop (and they're by no means mutually exclusive, as long as you're willing to pay for both), stay away from old tutorials. Recent versions introduced nice nondestructive things, like smart objects, smart filters, and layer styles. Those are much preferable to the destructive alternatives that we had to use in the past.