All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
You do not have to recite certain Soorahs of the Quran either during the day or before sleeping. However, you should recite a daily portion of the Quran during the day or during the night, to the best of your ability, and without designating specific Soorahs to be recited on a regular basis. It is stated in Majmoo‘ Al-Fataawa:
"Observing a daily portion of (voluntary) prayer, Quran recitation, Thikr (expressions of remembrance of Allah), or supplication at the two ends of the day and during hours of the night, and the like, then this is the Sunnah of the Messenger of Allah and the practice of the former and latter righteous slaves of Allah." [End of quote]
Shaykh Ibn Baaz said in his Fataawa:
"A person should recite from the Quran whatever he can. There is no specific portion that should be recited; he may recite (daily) one (page), two, three, or four pages; half a Juz’ (part), or a whole Juz’, according to his ability. However, he must not neglect reciting the Quran (regularly). If he recites the whole Quran every month or every two months, there is nothing wrong with that; all praise be to Allah." [End of quote, summarized]
It is an act of the Sunnah to recite Soorat Al-Mulk (no. 67) and As-Sajdah (no. 32) before sleeping, as authentically reported on the authority of the Prophet . Jaabir said: “The Prophet, sallallaahu ‘alayhi wa sallam, would not sleep until he had recited ‘Alif Laam Meem Tanzeel…’ (i.e. Soorat As-Sajdah) and ‘Tabaaraka Allathi Biyadihi Al-Mulk’ (i.e. Soorat Al-Mulk).” [At-Tirmithi and others, Al-Albaani: authentic]
As for the reported Athkaar (pl. of Thikr) and Soorahs to be recited before sleeping, please refer to Fatwa 330340.
Allah Knows best.