Then, put “Iowa gambling” in the search box on the left. In the new window, where it says “local root”, click “browse” and then select where you want to save the experiment to (when you get that far, you just need to set it up in advance). Click the one with the magnifying glass in the bottom right of the globe. Open PsychoPy, on the top bar you’ll see a group of icons with globes and little symbols in the bottom right.
I assume you have installed PsychoPy’s latest version (2020.1.3). It’ll be easier to get (1), for the moment. I’m going to assume you’re really starting from scratch here, so these are very basic directions.