First time pro-tips?

Hello, I have been browsing this community for weeks now, and I feel like you are a very loving and kind bunch. I feel okay asking this here.

So I've never smoked weed... or anything else for that matter. Ever. I've never been around it. I have some friends who do, and I just found out. Turns out, they're willing to share as soon as we are all free one day. They know I've never smoked, and they're all veterans at the game.

When I go over to their house, I don't want to look like an idiot. What are some tips you'd give someone who's trying weed for the first time? What are things you wish you knew the first time you smoked? What is the proper etiquette when smoking with friends? HOW do you smoke weed? Is it different from a cigarette?

Thanks for your help!