If i get a minor cut or scratch from a shaver at a barbershop will i get infected? i didn't bleed or anything but there is an 0.5 in long red line.

Unlikely: But without seeing this area it is impossible to diagnose. If the redness gets worse, spreads in area, you get fever or other symptoms, see a doctor asap.

Unlikely: Our skin is a large organ that serves as our first line of defense against infection. A tiny cut from a razor is not a significant challenge for us. Even if the blade from the barber was dipped in a petri dish of nasty microorganisms, the chance of getting an infection is still low . The fact that you did not bleed suggests that your armor (skin) was not compromised. Hence, unlikely infected.