Is there a community college where you live? That would be a good place to get started.
I recommend that you go to your high school guidance counselor or an officer at the nearest community college or university and ask them to administer some vocational interest tests, such as the Strong's Interest Inventory. There may be some tests online that you can take for free as well. Google "vocational interest tests" and "free online MBTI." The MBTI is like a personality test, telling you what you're likely to be good at as well.
There is a lot of financial aid available, some of which does not have to be paid back. Do not go deeply into debt to get your degree. It would be better to work part-time and go to school part-time.
You can start slowly by taking just one or two core curriculum classes, such as English and History. Everyone has to take those, so it's good to get them out of the way while you're deciding on what your major will be.
Warning: Do not go to a proprietary school, but do go to a state-run college or university. Those schools that advertise a lot and promise you the world have low academic standards, and I've seen people graduate from them knowling no mare than they did when they started. They are also super expensive, whereas your state university is publicly funded and tuition is kept as low as possible.
A poster on this board who calls himself Balaamsass has stated that he would like to start a fund to help JW's go to college. I don't know him personally, but you might want to PM him to see if he can help you get started. Also contact AAWA (jwactivists.org). They are a new association set up to help JW's. They are brand new, and may not have much money in their coffers yet.
Above all, don't get discouraged and don't give up. I graduated from college at age 37, after leaving the JW's at 32 and starting over. I had some help - lots of it.
I hope what I've said will get you started