What are the major doctrinal differences in a nutshell (asking as a non-Presbyterian)?
And how do they relate to “everyday” Presbyterians? Again, I don’t know either and would interested in learning.
Now you’ve opened a can of worms that has no bottom, no matter the label on the can: Presbyterian, Methodist, Baptist, etc. There is a comedian that does a take on your question using the Baptist derivation where he keeps dividing doctrinal matters in ever finer gradations until one person in the sketch makes the “wrong” choice in doctrine and the comedian pronounces the other party “heathen, bound for the fiery pit!!!” Obviously, it’s funnier to hear it with the various places where people have divided on seemingly inane/arcane bits of religiosity but it’s taken quite seriously by those who live it.