That waiver is almost impossible to gain.
No, you cannot join the Marine Corps without a high school diploma or equivalent. A General Educational Development (GED) credential is considered equivalent to a high school diploma, so it would meet the requirements for enlistment. However, without a GED or high school diploma, you would not be eligible to join.
If you can test for and get your GED, you could. As a 9th grader without a GED or Diploma, no. NO branch of the military will accept anyone who doesn't have at the minimum a GED.
You should have a high school diploma.
Yes.
Yes, but it requires a waiver.
There is no college requirement to enlist into the Marine Corps. You do need a High School Diploma or GED though. If you wish to join as an officer, you can either go to Annapolis or go to college and then go to Officer School.
You can legally join, but you need permission from your parent or guardian.
High School or GED. Either is acceptable.
The Marine Corps limits enlistments of people with GED's to more than 5 percent per year, and you need a minimum score of 50 on the AFQT test if you have a GED. Your local recruiter will have more information.
The Marine Corps accept the GED as the educational requirement in a maximum of 5% of their enlistments. People with a GED must score a minimum of 50 on the AFQT to be considered.
The only way it's going to happen is if you test for, and get, your GED, which is the minimum educational requirement of all military branches.
High School diploma or GED, and the ability to pass the ASVAB
You need to specify a couple things. I.e., enlisted or officer and what military occupational specialty you're going for. Requirements will fluctuate to meet the Marine Corps' manpower demands, but generally a high school degree or GED/equivalent is required to enlist. In some circumstances this may be waivered. I'm guessing by the way you have crafted this question that you have not completed either High School or your GED. 15 Credits would serve as a suitable substitute for either of these things.