Minimum PC spec for Photoshop? and PC or laptop?

There are two things you need to consider with a laptop.

One, disk space. Image editing eats disk space. You can't expand disk space with a laptop, so sooner or later you'll end up with your desk cluttered with external drives. That has immediate workflow implications, as saving directly to external drives is risky and bad practice, and even Adobe officially warn against it. You'll need to save to local drive and copy over. On a desktop machine, you can just buy new drives as needed and put them in yourself. The machine I'm typing this on has 20 TB internal disk space.

Two, the GPU. I don't know how this new generation of Windows laptops performs in this regard. I'd wait a while, but you can assume that graphics applications are low on the list. This will be solidly geared to gaming at first. Generally, up to this point, most Windows laptops have had dual GPUs, a recipe for trouble.

The safe bet, right now, is a desktop with a Nvidia RTX 4000-series GPU. That's a workhorse you can rely on. The current sweet spot is the 4060, excellent performance with Photoshop, and not particularly expensive.

A third consideration might be added. Most laptops have so many manufacturer modifications and extra "helpful" layers that you can't find the operating system anymore. This is how the vendors put their own stamp on the product. All these extra layers tend to get in the way and cause problems.

What you want, for best performance, is a "lean" system with a basic Windows installation, no extras. You can't beat that for reliability and problem-free operation. If you don't want to build the machine yourself (which is what I've always done), there are plenty of businesses out there who will do that and custom build a machine.