Sorry, my bad. You are right in that regard....However, Goku has killed more than one person, over 9 in fact:
He has killed Buyon, Octopapa, Captain Yellow, Staff Officer Black, Tambourine, King Piccolo, Yakon, many Red Ribbon soldiers, Frieza (in Resurrection of "F"), and Kid Buu. Technically, he did kill Buu, he just came back as someone else. It's almost the same thing as Raditz killing Goku only for Goku to come back.
I'm also going to assume we aren't going by movies, filler, and GT. If we did, the count would be over 34.
But like I said, none of those are canon, so we won't count them.
No, but I saw this HILARIOUS video where Michael Jackson killed Frieza! I've also seen a few Pokémon videos with him in it!