Well that's something you should do really if you're looking for inventory. Inventories vary between the games so much that if you're looking for something specific from the inventory it's allways better to create your own. As with the own inventory you allways get the things you need.

Know it's a hard task, even more if you're a beginner or never have done invnetory, but with little ambition and help you should be able to do it. Here's some hints to the inventory, I can't answer to question 1 as I've never done it myself the second question I don't get really, if you mean the events (see event in the manual)of the panel then yes, if something different please clarify.

The inventory, in short, consist the following "items":
-The base inventory that holds everything, you can do this by structs if you wish to have more than one inventory on your screen at a time. But in basic inventory you don't have to worry about this.

-Slots that hold the items inside the inventory. Slots have id for item and panel(s) to show the item on screen. At first you can create this with one variable(for item id) and one panel (for the output). Store the item id to panels skills and use that skill id to identify the item. When you want more features to the iventory, you should really use structs. With structs it's easier to add new features to the slot, however it's also harder to work with them if you've not done that earlier.

-The items are stored as ID, or as struct if you want to, to the slot. Each item can be a basic structure that holds the name, id and so on. Store them to an array for easier picking up from the slots, as then you can use the id number to get item from the array and remove the loop to get the item.