Regarding Obligatory Parts Of Salah
Man is accountable for only fard prayers. The compulsory Dhikr in prayer is reciting Fatiha and a pert of Qur’an with it and Takbeer ( Allah o Akabr) for transition from one posture to another. In ruku you recite the praise of God and the rest of is open for dua durood and other Dhikr of your own choice. You can do these dhikr and dua in your own language.