Stereo is no different for guitar tracks than other tracks really - it just depends on whether you want the track to sound like it's coming from a single point or whether you want it to give the illusion of width. Like fjz says, there are stereo effects available like ping pong delays, stereo chorus, stereo flangers etc, all of which create width.
Sometimes you'll come across a track that's stereo (i.e. has a left and right side) but which still sounds mono - all this means is that both the right side and left side are the same.
You can still create a stereo effect from a mono track, by sending some of it to a stereo bus with a stereo effect on it.
The best thing to do would just be to experiment with some of the stereo configurations in Amplitude and see for yourself how they sound. For instance, having a different amp/cab setup on both left and right channels, but having the same guitar signal go to each channel, will create a stereo effect because each amp setup will sound different. It's the differences between left and right that create a stereo effect. The greater the difference, the wider the sound. For instance if you had the exact same amp/cab on both the left and right channels, but made the amp and mic settings different on each channel, you'd get some kind of stereo effect. But it wouldn't be as strong as if you had totally different amps/cabs on each channel, or if you had two different guitar parts on each channel. The closer each channel sound, the narrower the sound will be.
PS I wasn't aware I'd made a Smiths comment recently, or maybe I did but forgot about it?