How do I lose weight to help my hips and knees?

Why lose weight , control blood sugar, and exercise to begin with?
How much weight reduction is needed to see a benefit on hips/knees?
Why not just have a gastric bypass to lose a lot of weight?
New weight loss drugs, Wegovy and  Ozempic-  GLP1 mimickers.. is that an option?
Can weight loss /proper diet and strength training prevent/control Diabetes 
Types of Diabetes..Type 1- body doesnt produce insulin to control blood sugar, often seen at an early age

                                           Type 2- Chronic insulin resistence..body's cells dont open up or respond to insulin lowering blood sugar, which then elevates ones blood sugar over 100 and leads to issues with nerves (neuropathy, vascular issues , kidney and eye problems over time.  risk factors as this develops later in life are waistlines over 40 in men, 35 in women, so weight reduction and control important.

                                           Type 3 Diabetes--is there a link betw Diabetes and Alzheimers?   Does poor sugar control increase amyloid/tau proteins in brain?