If you won't be firing your clay, consider polymer clay, air-dry-clay, or epoxy clay if you intend to directly make the items you intend to sculpt. Use modeling clay if you intend to make a mold from your original to cast in another material.
Dishes intended for use with food must be made from a fired clay with an appropriate dinnerware-safe glaze. In addition, it's preferable to use a mid- to high-fire clay, which will be more durable and have a lower absorption rate than low-fire. Low-fire ware tends to be more porous, and thus unglazed areas at the base are more likely to absorb moisture that will harbor bacteria.
Pottery Clay must fire in a kiln to cure completely, and is the only type of clay suitable for making food-safe items. Air Dry Clay is not as strong as firing clay and not food-safe, but dries without the need for an oven or a kiln. Polymer Clay bakes in the oven to become hard, is paintable when dry, comes in many colors, and is often used for jewelry and figurines which have a resinous feel when finished. Modeling Clay does not ever dry, so it is useful in making objects to mold and cast, or for sketching where the artist wants to reuse the clay over and over.
Firm modeling clays can capture and hold fine details, which is much more difficult with softer clays. The softer clays are more pliable and easier to use for modeling by hand and when fine detail is not needed.