It is proper to add something special to the meal on the second day of Pesah to commemorate the Purim miracle. It was on the second day of Pesah that Ester made her feast during which Haman was hung, and it is thus appropriate to make some commemoration of this event – known as "Se’udat Ester" – on the second day of Pesah. This custom is mentioned in the Shulhan Aruch (490).
It is permissible to shop during Hol Ha’mo’ed for food that will be needed immediately after the holiday if one will not have the opportunity to make his purchases afterward, such as if the final day of the holiday is Friday and one needs food for Shabbat. Similarly, one may cook in such a case on Hol Ha’mo’ed for the Shabbat that immediately follows the holiday. Even though one may cook on Yom Tob for Shabbat by making an Erub Tabshilin, it is also permissible to cook on Hol Ha’mo’ed for Shabbat in such a case. Likewise, if one is planning a Se’udat Misva for after the holiday, and there will not be time to prepare after Yom Tob, he may make the food preparations during Hol Ha’mo’ed. In such a case, it is preferable to taste a bit of the food during the holiday.
In general, however, one should not make preparations during Hol Ha’mo’ed for after the holiday.
It is permissible to play musical instruments during Hol Ha’mo’ed, and the strings of instruments may be fixed during Hol Ha’mo’ed.
