British Expats - Simple question your answer will help tons of people

Today is August 27 and my interview is set this coming Friday.
I simply want to know the most commonly ask question. Please give us some highlights and points to ponder.
1. What are the procedures once you are already in the interview room?

2.What are the most commonly and/or frequently ask questions?

3.Do we have to bring a 2 x 2 Picture during the interview?

4.Is it also possible that we can take the Oath the same day as the interview?

5. Is the interview something that everybody should be stressing about every single day and night till the interview date comes?

It's cool to be kind and nice nowadays...
Thanks in advance and keep smilin' it does our body good.