Netherlands - Im going to amsterdam

[cthey]

Hello
I am going to Amsterdam in septemer mostly to visit coffeshops and have a fun time with my friends.
This is my first time im going to Amsterdam (hopefully not last, depending if i like it), i dont realy know much about the town but i know that smoking cannabis in coffeshops are legal.
I want every kind of tips from you guys who have been in Amsterdam.
What i should do and what i should stay away from.
I wanna be prepared for where me and my friends are going.

Some questions:
How is the staff in these coffeshops ? Friendly?.
Is it only allowed to smoke cannabis inside a coffeshop, or can i go outside and walk on the street on my way to something else im going to do.?
Does every coffeshop have Hashish and Marijuana to purchase?
Is it only Cannabis or can i like get cup of coffee or something?
Read something about that in some shops you shouldnt wear something that cover your head. False or true?.
A two part question
If i order some hash what amount can i choose between or is it like a price per gram. and do i get it prerolled or will i have the pleasure of doing it myself?

please add stuff that you think is important for me to know.