i knew a lot about bitcoin and cryptocurrency in general due to Andreas M. Antonopoulos.. you may find his youtube channel here: https://www.youtube.com/channel/UCJWCJCWOxBYSi5DhCieLOLQ
tons of very informative videos.. including intros to a person who has no idea about cryptocurrency (do they still exist?).
Yes he was also the first guy I really learned a lot from