How do you know if your getting the cold shoulder from a friend?

By how they interact and speak with you. Sometimes it might seem like they're trying to get away from or have nothing to do with you, if they even speak to you at all.

Plenty of verbal cues give such a thing away 🤔

By the way they are acting towards you.

they say things like, i wish you all the best, cliches are the worst

If you got the cold shoulder from a friend or anyone the first symptom would be that your shoulder would begin to chill, eventually to the point where it freezes over.  Very dangerous is cold shoulder from a friend disease