Is it better to read the Quran and complete it, or to memorize the Noble Quran, knowing that I have never completed the Quran before, and have only memorized the section "Amma Yatasa'alun" and a small part of Surat Al-Baqarah?

Combining memorization of the Qur'an with reciting it from the Mushaf (physical copy) is preferable. However, if this is difficult, memorization takes precedence due to the hadiths that encourage it, such as the hadith: "It will be said to the companion of the Qur'an: 'Recite and ascend, and recite as you used to recite in the world, for your rank is at the last verse you recite.'"

However, if a person is ignorant of the fundamental rulings of Islamic law, such as beliefs (aqeedah) and acts of worship (ibadat), then he must prioritize learning them over memorizing the Qur'an. This is because learning those matters is obligatory, whereas, from the Qur'an, only memorization of Al-Fatiha is obligatory.