If you want to learn the basics of custom inventories then this video will help you understand how to make one as well as the buttons that go inside it.
i was wondering if there away to hide the players inventory or is that not possible
How do you mean “hide”? As in to stop them opening it?
so when u open it up using a command where it only shows the inventory u made without the player inventory there
As far as im aware, its not possible to open an Inventory without the player inventory being shown. I do remember someone asking me that a while ago.
I will say if you wanted to hide the items in the player inventory, then you can, just store all the items of the players inventory and then remove them from the inventory before opening your custom inventory. Then listen for the closing inventory event and give back the players items. May have an issue if the player leaves while there items are removed