Don't bother with university unless there is something you passionately want to study. That is especially true of humanities subjects. Philosophy, Classics, the History of Art, etc, are fascinating, but unless you want to teach they're not much use. You'd be better off doing an apprenticeship.
I'd also advise them to be careful about relationships. Our culture puts way too much emphasis on them. Virtually every film revolves around the romantic happy ending. In reality, relationships are really hard. If it's good, and you meet someone you absolutely love being with, then go for it. But be careful. A bad relationship can ruin your life. And having kids with the wrong person is even worse. You don't have to be in one. This isn't 1930.
Finally, I'd say work on your people skills/communication skills. Learning how to get along with others is vitally important – good manners, eye contact, listening to what people say, etc.
Oh, and learn to speak well. Eloquent people, with a clear RP accent, are listened to. I'm not saying "talk posh," but like it or not, inarticulate people with strong regional accents get less respect. It may be unfair, but it's true.