i need someone to help me with basketball!
I'm starting my freshman year and I'm a girl btw. I've never played basketball before but i want to start but i have a ton of questions. For the most part i know all of the positions. I have a few questions. ***I know they're really stupid questions and obvious ones at that but I just really want to get this right and not let my future team down.*** please answer them!

~Questions:~
1. Who do you guard?! Is there a designated person for each player to guard? Like does the center guard the center, power forward guard the other power forward, etc.
2. What/Where is "the key" zone? (I've gotten a lot of mixed answers on this one and I know about the three second rule)
3. Does the three second rule in the key zone apply for all players? Like the one with the ball, the player guarding the person with the ball, the other teamates of the defensive and offensive team.
4. When is a free throw and what is the lineup for it (like on the sides)?
5. When is a throw in and which players do the throwing in?

6. Do you have to stay in your position at all times? Such as returning to your given position everytime you go to the offensive side of the court.

Sorry if i got some of my facts wrong. i'm just a newbie :\