Hebrew language programs are available in most major Israeli cities and many smaller ones and offer a variety of levels of Hebrew instruction.
The most common study format is five hours a day, five days a week for five months. Less intensive options are available in many locations.
Registration for ulpan is through your local branch of the Ministry of Aliyah and Immigrant Absorption (Misrad Ha'Aliyah veHaKlita).
Eligibility for free Ulpan is for 18 months from date of Aliyah.
In general, there are more programs, offering more levels of Hebrew, available in the larger cities - where Olim tend to start their lives in Israel.
The Jewish Agency for Israel instituted subsidised residential Hebrew-learning programs with Ulpan Etzion in 1949. Consult your shaliach for advice and to register for residential ulpan options.