How can a Muslim begin to learn the obligatory matters in Islamic Sharia, such as creed, duties, and major sins?

There are specific fatwas one can refer to to learn about creed and some rulings a Muslim needs, in addition to books about major sins, commands, and prohibitions, and the knowledge that is obligatory to learn. One can begin learning with a set of books, namely: "Usul al-Iman" (Foundations of Faith), "Al-Fiqh Al-Muyassar" (Simplified Fiqh), "Muharramat Istahana Biha An-Nas" (Prohibitions People Take Lightly), "Minhaj Al-Muslim" (The Muslim's Way of Life), and "Riyadh As-Salihin" (Gardens of the Righteous).