There's no substitute for studying bass.
Get one-on-one bass lessons with an experienced, motivated teacher.
I have been teaching electric bass (fretted and fret-less) and upright bass since 1980. I have studied with Jaco Pastorius, Jeff Andrews, Milt Hinton and Charlie Banacos to name a few, and working full-time as a professional musician.
I teach all levels and all styles. Learn sight reading, theory, improvising, and the right technique.