Is it permissible, while reciting, to read what is easy from a surah, such as reading only three verses from a surah you are still learning, until you master the entire surah?

Reading the Qur’an is one of the greatest acts of devotion, for which the Muslim is rewarded. It is permissible for a person to read as much of the Qur’an as he is able, and whoever finds it difficult to read the Qur’an will have a double reward. There is no harm in reading a few verses, and it is recommended for those who have memorized only a few verses to read from the Mus'haf for memorization and recitation.