Sukkot: Blessings: SheHecheyanu

First Night: Say she'hecheyanu after saying leisheiv ba'sukka (in kiddush), since she'hecheyanu covers the sukka and the Jewish festival
Second Night: Say she'hecheyanu before leisheiv ba'sukka (since it only covers the Jewish festival itself).
Note There is no blessing on building a sukka; it is covered by the she'hecheyanu in the kiddush.