How do you reference?! I'm afraid of failing if I don't learn soon!

The one and only thing I actually HATE about Uni is that they expect me to know how to reference. Straight off. There's no questions about whether we know, nor do they encourage you to come to them if you're unsure about.

I had never even come across referencing until I came to Uni. And yet, they just assume that everyone knows how to do it. And I've tried to follow what they do, what I've researched online on 'How To' but it's still not good enough.

I don't really know what to do. I'm at a loss as to how to approach a lecturer about or just referencing itself when everyone just expects me to know what to do. I feel a bit silly in all honesty asking about it because the responses will vary from "Oh you should have said sooner!" to "Really?! You've NEVER done it?!"

HOW DO I USE THE HARVARD REFERENCING SYSTEM?!