The Takbir for bowing should be said while bending down to bow, and the Takbir for prostration should be said when going down for prostration, and the Takbir for standing up from prostration should be said whilst rising, and so on.

There is no difference between Fajr prayer and subh prayer. They are the same. Fajr prayer consists of two rak’ahs. The time for Fajr prayer starts when the true dawn begins, and lasts until the sun rises.