You can, there is no problem at all, but you need to pour out the water before boarding the plane. You can drink water on the plane.
You can bring them, just bring empty cups inside.
Hello, you can bring them, as long as they do not contain liquid. It's best to carry the empty ones with you to avoid them being broken during checked baggage handling, because the luggage handlers don't care whether a fragile sticker is on it or not, they just throw it on. You can refer to this, hope it's helpful to you! If it is helpful to you, please give a “positive review” as encouragement for me, thank you!