Karaoke is a form of entertainment, not a place, as far as I understand. The place where people can sing karaoke would be a karaoke venue, e.g. a karaoke bar.
So, I got confused when I saw the phrase "go to karaoke" in a Japanese textbook (it was used in my task written in English; by the way in Japanese "karaoke ni iku", which literally means "go to karaoke" is OK). The article "5 Tips for Not Sucking at Karaoke" added to my confusions because "karaoke" means a place in the context.
How correct is it to say "go to karaoke" and "sing at karaoke"? How would you invite someone to go to a karaoke place?