There's no such thing as the perfect string height. It's always a compromise. Most manufacturers will
recommend a string height for setup, but this isn't written in stone and is, to a large degree, a personal thing. Some players prefer quite a high action.
For Strats, the recommended string height depends on the neck radius. I think most Squier Strats are 9.5" neck radius so, from the website I linked above, that means:
Neck relief: .010" (0.25 mm)
String Height (Bass/treble sides): 4/64" (1.6 mm)
Most electric guitars tend to be set up with low-ish string height, but too low and you'll get a lot of fret buzz.
Note that *some* fret buzz is expected and "normal" especially on heavily picked/strummed strings, but this shouldn't be so much that it can be heard through the amp, or that it starts to impact sustain.
Cheers,
Keith