What is the period and duration of engagement (khitbah) in Islam, and is reciting Surat Al-Fatihah part of the marriage contract (aqd al-qiran), and what is the ruling on reciting it during the marriage contract?

The engagement period is not set for a specific time; it is left for the prospective spouses to determine, and it does not take on the rulings of marriage. As for reciting Al-Fatiha at the time of the marriage contract, there is no evidence to support it, nor was it established from the early generations (Salaf). It is an innovation (bid'ah), and its recitation or non-recitation does not affect the validity of the marriage, for marriage has conditions and pillars by which it is contracted.