Any advice on treating osteoartritis in both knees and left hip?

Hello and welcome to EmpowHer,
I'm sorry to hear you are experiencing Osteoarthritis and would love to give you some tips on the subject.
First of all, I want to mention that inflammation in the joints will inevitably cause increase pain in joints in a person with Osteoarthritis. That is why I suggest you look into implementing an anti-inflammatory diet into your life. A couple suggestions I can make are: no wheat, no rye, no barley, no dairy products, no sugar. That may sound like a lot but I have pasted a link below in which Doctor Chris Renna explains more in detail about how to maintain a anti-inflammatory diet without discomfort.
https://www.empowher.com/osteoarthritis/content/what-anti-inflammatory-diet

Other treatments can include:
• Alternative or holistic treatments
• Topical analgesics
• Lifestyle changes
• Surgery
• Physical Therapy
• Braces

Although there are many different approaches to treatment each doctor you see may have a slightly different opinion about what is best for you. So, I suggest that you get opinions from different doctors to see where they overlap, in order to find what is best for you.
Below I have pasted a link to a HER article that talks more about Osteoarthritis treatment:
https://www.empowher.com/osteoarthritis/content/osteoarthritis-treatment?page=0,0
I hope that helps.
Faith