Is there a certain age you have to be to buy nicotine gum?

Depends where. In california, you must be 18 years old [if you're younger, talk with your doc and your parents]. Younger age limit in the uk. So ... Depends on where you live. Congrats on making healthy changes.
Age to use nicotine . Teens and young adults rather need strong will and motivation to adopt and adapt a healthier life style that promote and facilitate smoking cessation. They all can. Adults with many sicknesses need urgent cessations and all that help need be applied.