How to get into shape without hurting myself by overdoing while I am losing weight?

Enjoyable low impact. Try to go to an introductory yoga or piyo (pilates/yoga) as a starting point. Being around other people with similar goals and having it overseen by a group leader helps keep you focus on correct form. Local pools also have pool exercise classes that help protect backs and joints. Make sure you enjoy the routine and that it is low impact. Walking is also a great starting point.