Start with How To Become A Social Media Manager - Beginners Guide (11 min, Flick), then LinkedIn Content Strategy: Post Ideas for Growth (15 min, Social Media Examiner). All 18 lessons here are free, from the teachers' own official uploads. You'll need phone tripod with remote, led ring light, product light box and a few more basics (about $125 of kit). The book to keep beside you: The Art of Social Media by Guy Kawasaki.