Start with How to Fix Tight Hips (WITHOUT STRETCHING!) (16 min, ATHLEAN-X), then 3 Moves Your Body Is BEGGING You to Do! (UNDO LOST MOBILITY) (11 min, ATHLEAN-X). All 24 lessons here are free, from the teachers' own official uploads. You'll need resistance band set, exercise mat, wireless headset microphone (about $110 of kit). The book to keep beside you: Daniels' Running Formula by Jack Daniels.