You choose the song YOU like the best and can sing the best, then you look at the list of songs provided by the person running the karaoke and see if it's there. I would prep 2 or 3 songs, just in case he doesn't have the one you want. My go to song is White Rabbit by Jefferson Starship which is from the 60s but I also sing songs from the 80s, 90s, 40s all depending on my mood. Choose rap, pop, metal, christian, it doesn't matter. Pick what YOU like.