What is the meaning of Welp?

Well. Typically used to express exasperation, a matter-of-fact or unenthusiastic attitude, or helpless acceptance of something surprising.

whelp, young mammal of certain carnivorous species, notably canine pup, bear - or lion cub

human youngster, especially of age group 8-11 in boy scouts

whelp

Alternative form of whelp

Source: wiktionary.org