Adventure games style mechanics?

I want to make a classic adventure style game. That means, I want to use items from my inventory on other items in the world to advance the story. I have an inventory already, but I can’t get my head around making a “drag paint on chair and change chair’s color” interaction.

I’ve spent months looking at “make horror game” and “make inventory” and “make quest tutorials” and I really can’t find a single clue to make this system. Can anyone kindly suggest where I should focus my attention? The more I search the more I find questions and forums filled with people who want to make this kind of game but no one finds a way.

Let’s make this question a good place to start!