In reply to slab_happy:
I'd always recommend beginners fitting with thin socks to minimise slippage between the shoe and foot
This soon happens as 'mank' builds (as it normally will) and shoes start to stink. Mank induced slippage affects beginner shoes worse in my experience (I was a no-socks fashion victim when I started climbing). Socks also helps the micro-fit. If the shoes stretch a bit, wear thicker socks. They then make great starter shoes for outdoor climbing that protect ankles from midge bites, ticks and stinging plants.
If a climber is lucky enough to not suffer from foot sweat problems, maybe its less of an issue.
For the OP: Beginner shoes should be wearable for hours with a snug, but not tight, fit. If shoes feel at all painful when trying them on in a shop, they are the wrong model, or too tight. Also look out for shoe companies that run free trials of various models at certain climbing walls.