ameer

Q: Can you tell me the difference between a Muslim and a believer and can you please tell me the responsibility to be a ameer for my country like how to be an ameer and so on?

Q: For a person to be an ameer, does there need to be an Imaam? i.e its mentioned in the hadith ومن يعص الأمير فقد عصاني so for a person to be an ameer which is meant in the hadith does there need to be an imaam?