Yes he does but without knowing I would say, If you watch Goku as a child in Dragon ball he kills off a good number of the Red ribbon army
he kills buu
In Dragon Ball Z, not counting movies or specials, Goku only killed two villains, Yakon and Kid Buu. But as child he killed a lot to most likely due to not understanding what it is all about to take a person's life at the time.
yes,he has killed many,in dragonball ,several red ribbon members,Tambourine,Drum and King Piccolo,and Granpa Gohan when he was Oozaru.