Originally Posted by .alhamdulillah.
If you want to learn Aqeedah, then the best book you can refer to is Sharh Al Aqeedah Al Tahawiyya. It's the book written by Imam Tahawi and it's the most authentic book on Islami Creed in the Muslim world.
Alongside, if you want a quick guide, then refer to Nullifiers Of Islam, a book which explains which activities will make you a non-Muslim, and we think it's easy, we know it all, but not really, we commit so many sins often that may lead us to acts of disbelief. So to understand Islam, you can refer to this book. Hope this helps.
If you want, read As Seerah An Nawawiya, by Ibn Katheer, it's about the Prophet's life. Hope this helps.