Without specifics of your symptoms or pathology, I can give general guidelines. Lower back therapy should be in the direction of core strength, stretching the hips and hamstrings and learning to lift and bend properly to prevent over-stress. Pilates works well for most of this taught by a PT.
For the neck, range-of-motion and strengthening would be what should be considered. See:
https://neckandback.com/pre-and-post-op/around-the-world-neck-exercises/ and
https://neckandback.com/pre-and-post-op/neck-situp-exercises/
Dr. Corenman