I've been trying to learn how to use the Cycles engine but when ever I set the viewport to shading I get loads of bright pixels in the render and I've messed around in the settings but couldn't find a way to fix it.
There are few things that can be used to decrease the noise in the final Render. First go into the view layer properties tab, Passes->Data->Include->Denoising Data(tick this one). Now go in the compositing tab and create a denoise node and connect it between the Render Layer Node and Composite Node like the pic below. Then render it, you'll get a clear Output.
The "loads of bright pixels in the render" are just ordinary noise, but are probably not fireflies. "Fireflies" refer to a specific kind of noise, which are caused by samples converging to unlikely results, thus leading to pixels being signigicantly brighter than they should. Certain microfacet distribution models such as Multiscatter GGX are known to cause fireflies, while others like Beckman or GGX are less affected. This is also why you should only switch to Multiscatter GGX when dealing with high roughness shaders.
So as long as you aren't using shaders or microfacet distribution models that are likely to cause fireflies what you are seeing probably aren't.
As for how to fix it, there are two simple ways to do that.
The first is using AI Denoising such as OpenImageDenoise or OptiX.
The second is by experimenting with the Clamping values under Render Properties->Light Paths->Clamping.