Dua

la ilaha illallah ( there is no god but Allah)

wallahu akbar (and Allah is the greatest)

la ilaha illallahu wahdahu (There is no god but Allah, the One)

la ilaha illallahu wahdahu la sharika lahu (There is no god but Allah, the One, having no partner with Him)

la ilaha illahu lahul mulku wa lahul hamdu (There is no god but Allah, the One, Sovereignty belongs to Him and all the praise is due to Him)

La ilaha illahu wa la hawla wa la quwwata illa billah (There is no god bu Allah alone to hum belongs praise and He is the sovereignty and He is able to do all things)

if a person says this during a day or a night or in a month and that person dies on that day or that night or that month, all their sins will be forgiven

Rabbi inni lima anzalta ilayya min khairin faqir

"My lord, indeed I am truly in great need of any good you may send down to me"

Astagfirullah al atheem alathee la ilaha illa howa Al hayyul-Qayoom wa atoobu ilayh

Zayd ibn Harithah reported: The Messenger of Allah, peace and blessings be upon him, said, “Whoever says this supplication, 'I seek forgiveness from Allah Almighty, besides whom there is no God, the Living, the Sustainer, and I repent to him,' then Allah will forgive him even if he fled from battle." [Dua that will erase all your sins]

Allahuma magfirli warhamni wa a'fini wahdini warzukqni

(say it between sujoods; asking for good in this dunya and Hereafter)

Allahumma infani bimaa allamtanii wa allimni ma yanfaunnii

O Allah, grant me success in what you taught me and teach me what is good for me [for studying]