PSD has very little to do with making websites; it's just an image format.
Start with making BASIC websites. Add a single image on each page. Then move to a server setup, with PHP instead of HTML. Then make a single PHP page that works as many different HTML pages in a browser, sharing a...
Have no ulterior motive but getting to know them, and making sure they're comfortable with the conversation. Then go over, ask if they mind if you join 'em, and introduce yourselves. Then just get to know them: ask what they're studying, what they do for fun, etc. The rest will happen...