Select Variable Product
In the drop down when you begin creating a product from your dashboard, select variable product from the drop down.
This type of product allows you to select variations of the product and charge them accordingly. You can also add your own attributes however this is not recommended since it will limit how people find you. You can select a start time and end time for your item, the date for the event and more. Make sure and set the stock number or you will end up double booking yourself.
Under variations you can also set the stock quantity but double check all numbers often as this has been known to be buggy. There are some tutorials on how to set this without the numbers changing and I will provide those links below. You can also buy a prebuilt shop and profile that already has products created so that you do not have to worry about doing anything from scratch.