Turning right into the left lane?

I’ve been told different things and I’m so confused. If I’m at the traffic light turning right. Do I turn into the left lane or right lane? I was on a drive yesterday and I turned into the right lane as all the cars coming straight were going into the left lane and I would’ve collided with the going left. I was told that was the right thing to do. But others have told me always turn left. What do I do for my test coming up next week?