SSD/SSDI requires a certain work history - usually at least 3 years to be able to qualify. There are some VERY complicated calculations to determine eligibility. The work must have been done in recent years, they look at the quarters worked apparently; after age 25 the goverment will send you a notice each year about your eligibility and estimated payments for your retirement as well as disability eligibility/payments.
For right now, SSI is possible, as well as other programs for people like food stamps, medicaid insurance & there may be others I'm not aware of....