Starchy foods are high carbohydrates, which it needs to energy your body. As you question about potatoes - no, fresh potatoes don't have any soduim but high carbohydrates.
If you want soduim free potatoes then add no salt to boiled water or meal. If you want low soduim then no salt in boiled water but salt on your dinner.
It's normal to have salt in some of starchy foods like breads, rolls, toasts, etc. but it's important to limit soduim in your body, that's all.
