Slot Inventory suggestions and help

Hello everyone. I was hoping that you could give me pointers on how to design a slot inventory system like in “Escape from Tarkov” (EfT) and “DayZ”. I prefer more of the EfT style in how it is designed and laid out. I know very little about how to do these type of things so please explain like I am five. So in my game HUD widget how would I set it so that there would be a space for a backpack. When the player finds a backpack it would set the image and then get that items inventory. Would I have to create a blueprint for that item for its own inventory but would I also have to make a widget for it so the items show up in the inventory? Or is there something I could do in the inventory screen that would get how many inventory slots it has and what items occupy them? Then be able to close the inventory slots to make it neater so they show up on screen. I am not asking that someone to please do this for me because I really want to learn how to do it. All I would need is walkthrough or something like that. I am creating a game that is far bigger than my breeches but it is something I am very passionate about and am willing for it to take years to finish.

This is just me thinking about a basic layout for it. So please tell me if there should be anything I do different
I want a blurry background when the inventory comes up. I would set an image panel on top of the canvas. Place my image. Then place 3 boundary boxes, one for whats on the character (how would I add multiple pages to switch between like a map and stats on this same box?), the container inventory (backpack and others), then looting. Set the looting box to hidden. Then in the character box I’d add an image panel to set a blacked out image of the person. Add in some more boundary boxes for clothes, weapons, gear. In those I would add a text block and an image panel. Then for the two box i would do the same. The blueprint part is where I have trouble and make this all work.

Here is a link to the EfT inventory for anyone that doesn’t know this game and to visually show what I would like:

Did you ever figure out how to do this? I am looking to model my inventory off of EFT as well.