There are numerous threads answering your query to be found in this forum, but here are some comments and suggestions:
1. BZ for thinking out a career plan to include college and life post Navy.
2. You should be focused on qualifying at prototype and nothing else until you earn your NEC, but...
3. Work your tail off and qualify as soon as possible, meaning if you can do it in 15-20 weeks, sacrifice your free time and go for it, because...
4. Once you qualify you go on staff hours and regain your life, then while you are waiting for your class to graduate you can work on college by...
5. Taking every CLEP and DSST/DANTES examination available free of charge at your base's Navy College Center. You could basically take care of a year or so of general education requirements by passing all the exams. For more info go to:
getcollegecredit.com
6. After you qualify, take the ACT and SAT free of charge if your HS scores were average. The ACT is much more realisiticr in my opinion than the SAT and most colleges accept the ACT and SAT. You might also find that you are better at test taking after completing A and C school. For example, I took the ACT in HS and got a 23 composite (highest is 36) and a 1090 combined SAT. I did the ACT again after becoming a nuke and scored a 29/36.
7. Try and get as much free college credit out of the way before going to the fleet, because once you get there, you won't have the free time available until you qualify all over again.
8. Try to become a Staff Pick Up instructor, yes it is two more years in the Navy, but both protoypes have local colleges that cater to a rotating shift schedule.
Good luck,
Jason