Read, read, read.
Read studies, read pitching books. Read training manuals.
Setting aside $10-20 a week toward getting certified and you will have that cost covered quickly enough. There are great programs you can attend, I know Eric Cressey does an internship program as well…again, not cheap.
You could get certified as a personal trainer. This would entail taking some classes at your local JC or online and passing the test. This does not mean a person is really qualified to be a personal trainer, but, it will increase ones knowledge somewhat and get some hands on/class room experience with that side of it. Get CPR certified. This can usually be done with no cost through a local school or city.
Volunteer to help coach youth baseball…13-15 year olds or assist with your high school team.
If you show up and say, hey I want to help, I love baseball, I played to such and such a level, I am CPR certified and have a training certificate…that is going to go further than, I want to help (which is fine too). Most college coaches at lower level played at the school or for the coach they are working with currently. Outside of that you may have to pay some dues by working as an unpaid assistant/trainer first for several years. Showing up several years from now at a college (or being recommended) and having some paperwork (CPR cert., personal trainer, NPA pitching cert.) and some practical experience (worked as a scout, worked as a high school PC for a couple of years) and a well thought out methodology and you may get a chance somewhere.
One thing for sure, because you are not a guy brought into a college program as a former player it is going to be an act of passion to get yourself to that point…dues paying time.