How to buy items (for self): To buy items, you can head to the store section in your watch menu. In the store you'll be able to purchase props, apparel or card skins by using star credits you have earned or purchased. However, there are also packs that are released throughout the year that contain limited edition items that are not available in the regular store. These packs are not obtainable with star creds and only available through real money purchases.
Owning items: If you purchase an apparel or non-consumable item from the store you now own it permanently in your Stash and can spawn it at will/wear it
Consumables: Consumable items like cookies or cigars are sold as individual items or packs, and are one-time-use only. Once they are spawned at the table they are considered used. You can store up to 99 consumables of the same item in your Stash. You can tell whether a prop is consumable or not in the store by it having a "C" in the bottom corner.