Yellow teeth

Okay so this may be off topic on this app but I need help. My teeth a yellow over years I have been drinking fizzy drinks and coffee and this may have affected my teeth. I recently just started drinking water and no fizzy drinks, and I don't smoke but I used to when I was younger that was couple of years ago. I know teeth whitening cost a lot. So does any of you know any good tooth paste or a home kit I could use?