Meanings and Conditions of the Shahada (La Ilaha Illallah):
https://www.troid.org/explanation-of-the-meaning-of-the-shahadah/
Understanding Imaan/Faith:
https://www.salafipublications.com/sps/sp.cfm?subsecID=SCL01&articleID=SCL010001&articlePages=1
^ 4 Parts to it
Lum’atil Itiqaad (Principles of Aqeedah of Ahlus Sunnah Wal Jama’ah):
https://www.salafipublications.com/sps/sp.cfm?subsecID=AQD02&articleID=AQD020001&pfriend=
Manhaj:
https://www.salafipublications.com/sps/sp.cfm?secID=MNJ&loadpage=displaysection.cfm
https://www.manhaj.com/manhaj/
Death, Grave & the Akhira:
https://abukhadeejah.com/the-life-of-this-world-and-the-hereafter-1-4-islam/
https://abukhadeejah.com/part-17-belief-in-the-punishment-of-the-grave-and-its-reward-foundations-of-the-sunnah-of-ahmad-ibn-hanbal/
Fiqh:
https://www.salafisounds.com/wp-content/uploads/2021/03/Fiqh-Its-Importance-and-the-Methodology-of-Studying-It-PDF.pdf
Salah (Prayer):
https://abukhadeejah.com/five-prayers-islam-importance-salah/
https://abukhadeejah.com/prophets-prayer-beginners-illustrations/
Fasting/Ramadan: