Restaurants are either TS or CS, not both. If the restaurant is a CS location, any 'entree' can be purchased with your CS credit. If the menu/board says the entree comes with fries, then the fries are included in the CS credit 'price'. If the entree is listed for one price and a side item such as fries is listed as a separate price, then the fries are not purchased as part of your CS credit. Your CS credit includes whatever that location calls an 'entree', plus a non-alcoholic beverage, plus a dessert.
Some CS locations obviously include more food in their choices than others. Park CS locations tend to run more to burgers and fries. Resort CS locations tend to have more and different choices, and their menus at dinner tend to be larger than at lunch, including full dinner items (salmon, ribs, half chickens, even steaks). You are absolutely allowed and invited to try CS locations at any resort; Disney hopes you will like it enough to book a stay there on your next trip.
I can't think of any CS location where any 'entree' item on the menu is off-limits or is an up-charge. It would kind of defeat the purpose.