I grew up (long time ago) in Wisconsin, so I always asked for "a bottle of pop."
Your choices were Coke, Root Beer, Cream Soda, and then a string of Grape/Cherry/Orange drinks that were so sticky-sweet you could use them for hummingbird food.
And yes, you could buy a phosphate at the soda fountain in the local drug store.
My kids grew up in California so they look for "a can of soda".
My grandson, the soccer fiend, tracks down a "sports drink",
and my Grandaughter, Miss Priss, requests "Juice, please."