Inventory

#1 This is not an easy question to answer. I'll tell you right now if you are looking for a block of code that you can paste in and have everything work you are not going to find it. This is something you are going to have to do a lot of research and work on yourself to implement, or you can pay someone to do it for you.

In the past I have used the DragDrop Button resource as a starting point. In all the projects that I've used it, I have always had to make modifications to make it work exactly like I want, so be prepared for it. Now, recently, Dave Young as pointed out that the ability to drag and drop things is built right in to the GUI in TGEA 1.7+, so you could also use that as a starting point.

If all of this seems "way over your head" then you may have to step back and take a different angle. Find someone more knowledgeable to help you out, or start with some simpler functionality to get yourself familiar with how things work. I'm not trying to be insulting or anything at all, but making a game is a lot of work and even features that may seem "simple" (like a drag-and-drop inventory screen) can be a lot more work than you might think.