Will u become dehydrated if you only drink caffeinated sodas and coffee and play sports

Yes caffenie doesn’t hydrate your cells and neither does carbonation

Oh yes, for sure. Drinking caffeinated sodas and coffee, especially the sodas, are substances with a lot of salt. Sodium and Caffeine can greatly dehydrate a person by increasing the solubility of the blood and fluids. This can and will suck water and keep water in the blood stream which is then filtered via the kidneys before being urinated. 

And naturally playing sports, which requires a lot of sweating can greatly decrease fluid levels.