BTW the best way to learn is to listen to pravachans of muni and acharyas in person.
try reading this book karma ka siddhant. Its available in english also Theory of karma. (I am yet to read but hear a lot about it).
Download the app Jain Bodh. and listen to Kshama sagar ji Maharaj karma siddhant. This was a life changing event for me the way he explained in his lectures.
Beware dont read anything which is not prescribed by the muni. Remember not all text is for reading by general public as your mind can go in wrong direction or derive wrong meanings out. Strictly follow what is prescribed for layman.
Lastly this is an opinion only, please due your due diligence.