Beginner's scripting question: Player control

Can somebody help me with these two beginner's questions:

1) How do I identify the player object in a .cs script?

2) How can I control the player? I need to do one or more of the following:
- query the player's position and direction of movement
- force the player to move in a specific direction (force a specific yaw)
- set the player's speed of forward motion

Apologies if this is covered somewhere - I tried to search the forums but found nothing. Maybe this is too basic?

Thanks for any help!