Charlene,
What on-site college will do for you is expose you to a lot of different kinds of people from around the country and world, which is an education in itself if you have lived only in one place. When I went to college, I didn't even realize there were bad people in the world. The other thing it will teach you is, if you have good professors, is how to expand your mind.
They say you can't go home again, and you certainly can't go home with the same mindset if you are the first generation to go to college. There are some who play in college and never learn the serious stuff. Learn the serious detail in every class. You'll never know when it will be helpful.
Of course, the military will teach you many of the same things that college will. You will expand your mind, just not academically.
There are also online courses. I have a book that lists the colleges that have online courses and what their specialties are. I think the online courses are cheaper, but a family member doesn't think so. You can take courses toward a degree, or just take what you want to. (As you know, there is the Gold certification with a DVD; so I don't get too far off the topic of mystery shopping.) My birdwatching magazine lists college courses in bird anatomy. My Master Gardener newsletter lists college courses, a couple of which are free, in various aspects of gardening. But back to writing. . . you can also take community writing courses. Some are sponsored by high schools and taught at night to adults. They might have a Community Education department. You can also take such courses at community colleges that are just for fun. Community colleges (two-year colleges) are cheaper than the four-year universities.
When I was in college, people over 65 could take a class 1/4 off. There were several interspersed among the students. As a Katrina victim, you probably not only can get special treatment for entry, but you might get a scholarship. All colleges have scholarship offices. Don't be intimidated by the application (After all, you use forms all day while mystery shopping.). Just ask for help.
There are also books on how to improve your writing skills. They are cheaper than going to college, of course, and you can find them at the library or at used book stores. The biggest mistakes I see on these posts are in spelling. There are community courses for improving spelling.
It's never too late to try, but you may have to take courses outside of the college level in order to find something that doesn't cost an arm and a leg. When I went to college, I paid $35 a semester hour (three hours per class, meaning you multiply 35X3) plus fees, but the last course our son took cost $800 including fees. $1,500 lasted me a whole semester and that included food and lodging. Both of us attended state universities which are cheaper than private ones.
Check with your local high school or college about "testing out". (High schools often have college-level courses.) If you know a subject, you can take a test without taking the class. If you pass, you get credit. Some courses are required and some are electives in college. If you take a course or pass a test for something you love that doesn't lead toward a degree, you may get credit for it as an elective (something extra that also counts).
I know a retired man who found out on his first job that high school didn't prepare him for anything. So he bought a grammar book and an algebra book and studied at his kitchen table every night for six months until he was satisfied with what he had learned. He had a very successful career.
I once wrote and sold a magazine article called, "How to Be Smarter". I love telling people about scholarships, the library, etc.
Sandra