The special schools for adults can be found in the larger cities. You should look for these opportunities on local level. You can contact the department of education (or equivalent) of the municipality level local government. To find the municipality level local government you have to search for this expression: „the name of the municipality + önkormányzat”. For example: Veszprém önkormányzat.
You can also search for this opportunity in Hungarian if you search for this on the Internet: “általános iskolai oktatás felnőtteknek + the name of the city where you plan to attend the program”.