Question

what does S/o, W/o and GP stand for

Answer 1

In what context? GP can stand for many things, but most commonly stands for "general practitioner, as in a doctor who practices general medicine (not a specialist).
The abbreviations s/o, d/o, w/o, h/o, etc. are usually used to denote familial relationships, such as "son of", "daughter of", "wife of", husband of", etc. These abbreviations are often seen in ancestral records.