From Pub 970:
• For at least one academic period beginning in 2018
(or the first 3 months of 2019 if the qualified expenses
were paid in 2018), the student was enrolled at least
half-time in a program leading to a degree, certificate,
or other recognized educational credential.
(The 5 month rule applies to the definition of a qualifying child student who needs to be full time.)
So you are eligible for the American Opportunity Credit if no one is claiming you as a dependent and you are otherwise qualified. Pub 970 has all of the gory details.
