Namaz er por dua korar niyom ki? Janaben please

Assalamu Alaikum bhai ra, apnader kache ekta basic question chilo. Ami Agrabad, Chittagong e thaki ar protidin 5 waqt namaz pora try kori, alhamdulillah. Kintu ekta beparta niye confused achi onek din dhore. Namaz shesh korar por dua korar shothik niyom ta ki? Mane farz namazer por sunnat namaz age porbo naki age dua korbo? Ar dua korar somoy haat tule korbo naki haat na tule? Amader mohalla te beshi bhai ra alag alag bhabe koren tai confused hoye jai. Keu bolen haat tule dua kora thik na farz namazer por, keu abar bolen kono somossa nai. Alim bhai ra thakle ektu clear kore janaben please, inshallah shikhe shothik bhabe amal korte chai. Jazakallah khair!