@Lost Equation in, indeed, a bit "lost." I can speak to this from having been a Naval Flight Officer who stays in touch with military aviation. Let me address his answers number by number:
1. If you have a GED even with a 4-year undergraduate degree you are not qualified to work toward military aviation. You MUST have a high school diploma from a brick-and-mortar high school and a four-year degree from an accredited college.
2. Good answer, with the exception of the fact that to be an AF pilot you MUST either graduate from the AF Academy or a 4-year AFROTC program. The AF gets 99% of its pilot candidates from those two sources. The Navy and Marines get about half of their aviation candidates through OCS, post-college.
3. Completely in error. If you are not an AF Academy or AFROTC graduate you are not going to get a flight training slot. If you are accepted to Navy/Marine OCS the only service which will guarantee you a chance at flight training before you start OCS - IF you meet all qualifications and successfully graduate from OCS - is the Marine Corps. For the Navy you have no guarantee.
When you are accepted for Primary Flight Training that is ALL you are accepted for. There are no "fighter slots" from the beginning, even for Marines who are guaranteed flight training and continue to meet the quals, there are only slots in Primary Flight Training. If you complete Primary Flight Training at the top or near the top of your class and if there are any slots for fighter seats available when you graduate you can put that first on your "Dream Sheet," but there are no guarantees of that at any point.
4. That was actually Step 3, it is out of sequence.
5. For Navy and Marines, you get your wings once you complete Primary Flight Training...carrier qualification is PART OF Primary Flight Training in the Navy and Marines. THEN you find out what you are going to fly and head down the line to Advanced platform-specific flight training. After that, you still have to go through operational flight training with the RAG (Replacement Air Group Squadron) that actually complete your qualification to fly and deploy in your assigned platform. No matter what, if you screw up anywhere along the line you can wind up flying a less-demanding platform or even being removed from flight status entirely. @Lost got the AF part pretty much correct, but he forgot the mandatory training on how to wear the 6-foot white silk scarf.
@Anonymous is correct about the Academy or ROTC requirement for the AF and the need for a STEM degree, HOWEVER he is in-error in stating that is a Navy Marine requirement. The Navy and the Corps rely on the aviation-specific testing they do which has proven to be a better indicator or aviation performance. The Navy and the Corps DO NOT require or even necessarily prefer an engineering or STEM degree, but you need to have a REAL degree (not Underwater Basketweaving or Criminal Justice) with a decent GPA. That is the way it is and the way it has always been. I spent 10 years as a Navy Airborne Electronic Warfare Officer with my Psych degree, I knew VERY few Navy or Marine Aviators (pilots and NFOs) who had technical degrees, and the only Navy?Marine Aviators (real ones) who post here also have degrees like Political Science, not engineering or STEM.
Bottom line - your chances of flying fighters in any service are less than if you try to make it to joining a SEAL team. The difference is that you can be attrited (failed) at any time over a period of a couple of years instead a few days or weeks.
You want to try to be an AF fighter pilot (Yawn!) then you need to hit the books, get your graduating status in the top 5% of your class, show "community involvement/service," and play a sport or two so you can shoot for USAFA or a 4-year AFROTC program and get your engineering degree.
If you want to go for Navy/Marine Aviation then you flexibility is greater. Do the same things you would to get into USAFA or AFROTC an decide if you want to go to the Naval Academy (where the worst officers in the Navy are created), NROTC, or just do a "walk-on" out of college...and while you should shoot for the best grades, you do not have to have a 3.9 or an engineering degree. Even with that you will have to take a standardized academic test (ACT on steroids). It is TOUGHER to be a Navy/Marine Aviator and the washout rate is higher.
As for sports, I would recommend soccer and wrestling. Soccer teaches you teamwork and situational awareness (great aviation benefits) as well as gets you as fit as any sport can, and wrestling helps develop burst energy and the muscles necessary to better withstand G-forces.
Be realistic and create a plan that allows for changes in your wishes and changes in the needs of the military. Good luck.