In order to memorize the Qur’an, you need to read it correctly first, and this is done through one of two ways:
1- Being a student at the hands of a Sheikh Hafez and reciter of the Qur’an.
2- To follow some computer programs designed to memorize the Qur’an.
As for tafsir, it must be studied by a scholar specialized in the science of tafsir, and it cannot be learned like this.