How do you get comfortable talking to 16 and 17-year-old boys who are your stepbrother's friends if they are Scottish and you can't understand them much?

One thing the whole world has in common is music! Listen to your favorite groups of singers or singer and dance and have a good time. Eventually, being around them more you'll get to understand them. I have a brother-in-law who is Australian and it took me a few months to get use to his accent (sounded like he was talking with a mouthful of marbles and accent to boot! LOL) If one or more the boys talks too fast don't be afraid to tell them to slow down because you can't understand them. They'll oblige you.