Can one rely on a single book to learn the interpretation of the Qur’an, and what are the recommended books of Tafsir for a beginner, and should one memorize the Qur’an before learning Tafsir or learn them concurrently?

There is no objection to limiting oneself to a single book when studying Tafsir (Quranic exegesis), especially for a beginner. For a beginner, "Al-Tafsir Al-Muyassar" (The Facilitated Exegesis) or "Al-Mukhtasar fi Tafsir Al-Quran Al-Kareem" (The Concise Exegesis of the Noble Quran) are recommended; both are available on the 'Ayah' app. "Aysar Al-Tafasir" (The Easiest of Exegeses) by Abu Bakr Al-Jaza'iri is also recommended. Memorizing the entire Quran is not obligatory, and it is preferable to combine memorization with reading the tafsir of what is being memorized.