Start by adding an Array object to your project. Arrays are used to store multiple values in a single variable. They work like tables (rows and columns).
In the properties set the Width and the Height. Example, if you only have one item, let's say an HP Potion, your array could be set to Width 1 (one row for one item) and Height 3 (three columns = name, hp, qty):
Array object items [name][hp][qty] => ['HP Potion']['45']['2']
If you have two items (HP Potion and MP Potion) the array could be set to Width 2 and Height 3:
etc. etc. if you have more items.
You can add as many rows and columns as you want depending on how many items you want to include in your game. Maybe use an array for your items and an array for your weapons if you have any.