To become citizen... You need to pass the citizenship exam.
If you have green card and one of your parent become a United States citizen before you turn into 18, you do not need to take an exam. Even this, you still needs to apply and take an interview.
You only need to wait 3 years for citizen if you get your green card because you marry with a US citizen. Other than this, you need to wait 5 years. Both needs to take an English and US history exam,