Just want to help remembering commands. Answers are in this good article, 
Learn Vim Progressively.
1. How to go in
 insert mode?
2. How to 
return normal mode?
3. How to 
delete the character under cursor?
4. How to 
save and quit?
5. How to 
delete (and copy) the current line?
6. How to 
paste after current cursor?
7. How to 
move the cursor without using direction keys?
8. How to 
get help about command?
 
Question 1:
ReplyDeletei - insert text before the cursor.
I - insert text before first non-blank character in the line.
gI - insert text in column 1.
gi - insert text in the same position as where insert mode was stopped last time in the current buffer.