I want to be an officer in the marines, as I feel im a born leader. But I also want to enlist. What do I do?

I am a sopre in high school and have realized that I am a natural leader. For a year now I've had this strong empowering feeling inside me that the marines is right for me. Problem is I'm not super strong. I'm 5'10 and still growing, but sort of scrawny. I'm working on it but I have this idea in my head that I won't be ready for the physical requirements. I also would like to know about the NROTC program. I read about it but I don't quite understand it. I also don't want to be in some job I don't like. I want to enlist but i dont think that would make much use of my leadership skills. MWhat I want is to be leading marines on the field. Not necessarily being the first one through doors or anything, but on the field nonetheless. I need guidance.