How to make a Inventory Hotbar

Hey Guys! I would like to make a inventory, were you have 4 slots on the left corner of the screen. The 4 slots correspond with the number keys 1,2,3,4. Much like the one "Hello Neighbour" inventory system uses. Where you press on a item and i comes to your hand/inventory. I'm also not the best at scripting, so if you guys know any good tutorial or know a way of making what I want. It would be really appreciated. Thanks again, Secret_Gamer!