[@CaughtInTheRiddle][@Ermine][@The Harbinger of Ferocity]

Thank you for the replies everyone! 

I'm really a beginner as in: i've been watching Critical Role for 30 episode which I love, but that's literally it. I'd love for someone to be able to explain the basics and - if someone has time - could be able to send me some examples or would be willing to try something out. 

I've read some parts of the player handbooks, including one for the DM, but I honestly don't get most of it. Like how they determine what advantages you have in certain checks or when you have a disadvantage?? What?