2 questions about menues

Question no 1:
Is it possible to move the top menu to the left side of the site? I have the menu on top of the site but the structure of the menu goes to far to the right because I have many pages in the sub menues.

Question no 2:
I want a new menu to appear on the page you come to when you click on a link in the main menu. It is because I want to avoid complicated structures in the menu where you have to go back to the main menu all the time to find the other pages in the topic you are looking at. If you click on “Food” in the main menu all the other pages related to that subject should be reachable from the “Food”-page instead of from the main menu.

I’m using the twenty twelve theme.