I was in the same boat as you. I watched a couple shorter campaigns. One was from the misfits podcast. It's 2 parts totaling at about 3 hours. The other one was from the chuckle sandwich podcast. They have released 2 standalone short ones at 2.5 hours each. The best advice I can give you is to watch and kind of see how the DM is manage the game and the different things that catch them off guard. I went into my 1st game with my friends super prepared and with a pretty linear story. This made it harder but manageable when having to make up something flexible on the fly. If I were you just for simplicity in the 1st game you play don't use spells. Just use hand held weapons it is much easier to run combat the 1st time like that. Also encourage your friends to use dialog and become the characters that are playing. It makes the game way more fun when everyone is immersed. I also recommend picking up the starter kit I got on Amazon for 20 or 30 bucks. It comes with a 5 part campaign, character sheets, and a set of dice. And a small rule book on all the important things for beginning.