You can get Medicaid until you are 21 with a low income, and that would have covered your ER bill. If the bill is 3 months old Medicaid might still cover it. But get to your Social Services dept and apply. A case like yours, going to an ER uninsured, is exactly why the Obamacare is necessary. What do you think happens to health care costs when they treat you and you pay nothing? They increase the cost of services to insured people then then have higher premiums to pay. You should go first to an urgent care clinic or county clinic and pay a small fee. I really wish the federal mandate to treat everyone at the hospital ER would be repealed.
Being a student has nothing to do with health insurance. Some colleges have a health center which you pay a student fee for.
Although you're asking about getting health care, I think you mean health insurance. You get health care, by going to a doctor. If you want someone else to PAY for it, you're talking about health INSURANCE.
Florida doesn't give welfare health insurance (medicaid) to able bodied adults. Community colleges typically don't offer group health insurance.
Depending on what your ER issue was, if you are otherwise healthy, you should be able to buy a high deductible health insurance policy for under $100 a month. Keep in mind, these typically have a deductible well in excess of $2,000. A reasonable price for a comprehensive health insurance policy, at your age, with no deductible, if you're PERFECTLY healthy, is $250 a month.
Seriously, your best bet, is to look for a different full time job, where you can get benefits through your employer. Or if you can squeeze it in, another part time job at someplace like Starbucks, UPS, or Walmart, because they offer health insurance to part time employees.