hmm...seems like you want the front end before the back end...
Okay, you want to learn to fly now. You don't have to know how to fly to get in the process for Marine Aviation: just have the educational and physical qualification to ensure that you can. Knowing how to fly is an asset, but not needed: they teach you to fly if you are capable of learning how to do it.
The main thing is to have a college education that guarantees they'll select you for aviation...now. an aeronautical engineering, or other practical engineering degree can do this. You need to start on the road for this, in high school, by taking the appropriate high school classes, like algebra, calculus and other things in high school now.
Remember, there is three big routes to getting what you want:
1. admission to the Navy academy, with conversion to the marine corps in your junior year, and then after graduation and of course, quantico and selection for aviation.
2. College degree in hand, you apply for marine officers school (quantico) pass it, and apply for aviation
3. Marine ROTC (college again first), quantico, and application to marine aviation
4.
This is usally the last resort, but it will work: Finally, enlistment in marine corps, college along the way, selection for officers canidate school, quantico, and then marine aviation.
In all these scenarios, you notice you have to pass the boot camp for marine officers, before you can go further. You have to be a marine first guy.
Now if you want low cost flight instruction:
USAF aeroclubs on the bases are formed just for that purpose. check and see what kind of rates they offer
Boy scout (Yes boy scouts) Explorer aviation groups sometimes have member that have aircraft that can be used to further your education cheaply. check a local district BS office that might have a post close to you to try and find an aviation post near you.
shovel a lot of snow and get a lot of money to get the flight time.
Its up to you. Go get your dream young man.