For All moms need answers

I will be a first time mother if this pregnancy sticks so I need a few questions answered by you ladies because I am completely new to this

How often should you drink water?

Can I drink Coffee?

Is it safe to have sex a lot early in pregnancy?

Can you go on vacation before 5 months? ( in the states and out the country?)

what is safe to eat during pregnancy and what is not ?

and do you tell people after 12 weeks or 20 weeks ?