I you don't explain what you are trying to do then we cannot determine whether you are asking the right questions. There is no point in asking about state machines if a state machine is not an appropriate solution for your problem.

"I have seen on this forum what happen to those who write their projects directly:)"

If you ask us to write your code for you the response will probably not be very useful. If you explain your project clearly then say 'I think I should tackle it this way, does this seem sensible?' you will get useful responses *even if it is homework*.

"so its better that i should put things in HIGH and LOW format only."

That's very digital, but what does it mean?