As for your karma question, that is a part of Buddhism I personally havent studied in great depth, so another DUer would be a better source in terms of strict interpretation. I view karma more along the lines of this talk https://imcw.org/Talks/Talk/TalkID/1401 which centers on our karma being in our own hands, our own creation, depending on which seeds we water and nurture. She analogizes our past karma to a block of salt whose potency/impact depends on how large a body of water its in, i.e., the extent of our efforts to cultivate a kind heart, etc.
This teacher isnt one I follow, but IMCW is a great organization/website and has wonderful free talks, supported by folks contributions (dāna). I especially find Tara Brach a great teacher, shes not only a Buddhist community leader in DC but also a clinical psychologist, so she is adept at integrating Buddhist concepts and tradition with personal, practical application of the teachings.
Enjoy your journey. 🙏