Trying to know WordPress

What’s I don’t know:

What do I mean by “H” ?

I am learning to Quote! How to put ” in the end?

I don’t know citation! Manav!

I still have to re-run code, but may happen! I of course knew: 
# include <stdio.h> 
int main ()  {
 return 0;
}

What to do with Classic? Have not sure at all! 

What's Pre-formatted? May be it looks nice! 

Now, what to do by Verse
Isn't it same as preformatted? Just small size? 

The end!