Seeking a Self-Study Plan to Understand Islam Deeply

Assalamu alaikum, I'm someone who hasn't been practicing but now I want to study Islam seriously to build a real understanding of the faith from its own sources. I know there are formal paths like studying at Islamic universities or becoming a scholar, but I'm looking for a self-taught route. For those of you with knowledge, what subjects should I cover and in what order to slowly build a solid foundation? I'm especially looking for advice on: - What areas of Islamic knowledge are must-learn, like Qur'an, hadith, fiqh, tafsir, aqidah, Islamic history, Arabic, etc. - Which subjects to start with and what comes later - Foundational books or resources you'd recommend - Whether I need to learn Classical/Qur'anic Arabic and how much - How to understand the differences between schools of thought and their disagreements - Common mistakes self-learners make I'm aiming for a long-term roadmap from beginner to advanced. Since I'm coming from a non-religious background, I'd appreciate resources that help me understand Islam on its own terms-theology, scholarship, history, and intellectual traditions. Jazakum Allahu khairan for any guidance.