Don’t buy plastic water bottles.
Invest in one decent insulated bottle. The double walled ones are best. Stainless steel is great.
Personally, I bought a Thermos Hydration Water Bottle with Straw, Magenta, 530 ml. This one doesn’t keep it cold, but it never leaks. I have one at home, one in my dance bag, and one in the office. Highly recommended. (pic below is of the stainless steel ones)