This coming Shabbat is very special and unusual. It is one of those rare Shabbats that three Torahs are taken out and read.
The first six Aliyot are for the regular Torah reading of תזריע. The seventh Aliya is connected to Rosh Chodesh. And the Maftir is read from שמות י״ב and is known as פרשת החודש.
Since it is the first day of Nissan, we are to study in earnest, the laws related to Pesach preparations. Many of the details are mentioned in this special Torah reading.
The corresponding Haftarah for פרשת החודש, is read from the Book of Yechezkel, that also deals with Pesach and its unique Halachot.