Weak glutes are a common symptom from sitting too much and then other muscles around the hips compensate which causes multiple issues with hip tilt and gait.
For upper, I'd highly recommend adding rear delt flys and face pulls at twice the frequency of any chest or shoulder workouts. Most people have overdeveloped front delts and underdeveloped rear delts and that can cause severe imbalances.
Also for upper (especially if you get neck pain or upper back pain between shoulder blades): Traps (shrugs, reverse fly, and/or face pulls are my preference)