Surah Al-Baqara 2:1 — translation and meaning

Alif Lām Mīm – letters like these begin certain sūrahs of the Qur’ān. Although they have no meaning in themselves, they do however have a purpose. Since there is divine wisdom contained in everything in the Qur’ān, these letters point to the miracle of the Qur’ān, made up of the letters which make up the words we speak. Therefore, when sūrahs begin with letters in this way, they are usually followed with a verse about the Qur’ān, as we see in this sūrah.

Source: Al-Mukhtasar Tafsir — Tafsir Center for Quranic Studies.