Wa alaikum asalam,
If you had recently left Shi'ism. I don't recommend that you jump right into the Ash'ari, Maturidi, and Athari controversies straight away because it's a giant headache filled with so many semantics, going around in circles, etc. What I do recommend though is to focus on learning about the Ibadaat (i.e. Prayer, fasting, Hajj, etc) based on the Shafi'i madhab. Focus on reading the Sirah of the prophet, purification of the heart, reading the Quran with a simple Tafsir on the side to reflect upon the meanings, etc.
As for Aqeedah, go through Aqeedah al Tahawiyyah with someone that can explain to you the book in detail, and just stick with that. The reason is that the information from Aqeedah al Tahawiyyah, as far as I know, is agreed upon by all of Ahl al-Sunnah. So I recommend you stick with that for now.