Okay kiddo, so you know how sometimes we have to do things or go places? Well, when grown-ups say they have to "go", it means they need to move from one place to another.
In the game of Go, it's kind of like playing on a big board with squares. We have to take turns putting little pieces called stones on the board. We can put the stones in different places, but we have to be careful because sometimes the other person might try to take our stones away.
The goal of the game is to try and take over as much of the board as possible, while making sure the other person doesn't take over too much. So when we say "go" in the game of Go, it means we're taking our turn and trying to make the best move we can to win the game.
Does that make sense, little one?