1st Pregnancy: Need Advice

Dani
Okay, I'm 4weeks and I have never done this before. I'm virtually going in blind here. 
So, tell me what I need to know. 
What can't I do?
What should I do? 
What is going to happen I don't need to freak out when it does? 
Give me the advice you wish you'd have know , please. 
I feel like there's SO much I don't know.  
Thank you in advance.