PROPHET MUHAMMAD SALLALLAHU ALAIHI WASALLAM SAID:
IF YOU CAN'T REMEMBER ALL THE DUA'S, SO JUST LEARN THIS ONE COMPREHENSIVE DUA.
1492. Abu Umamah (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) made many supplications which we did not memorize. We said to him: "O Messenger of Allah! You have made many supplications of which we do not remember anything.'' He said,
"Shall I tell you a comprehensive prayer? Say:
`Allahumma inni as'aluka min khairi ma sa'alaka minhu nabiyyuka Muhammadun sallallahu `alaihi wa sallam. Wa `a`udhu bika min sharri mas-ta`adha minhu nabiyyuka Muhammadun sallallahu `alaihi wa sallam. Wa Antal-Musta`anu, wa `alaikal-balaghu, wa la hawla wa la quwwata illa billah
(O Allah, I beg to You for the good which Your Prophet Muhammad (PBUH) begged of You; and I seek refuge in You from the evil where from Your Prophet Muhammad (PBUH) sought refuge. You are the One from Whom help is sought and Your is the responsibility to communicate (the truth). There is no power or strength except with Allah the Exalted, the Great.'''
[At-Tirmidhi Riyad-us-Saliheen 1492 ]