Daily walking is a good start. Also look into versions of pushups and rows where you're semi vertical to reduce initial body strain while cns gets used to the movements. Body squats are good too, but make sure that you understand form for those, easy to make mistakes that damage your knees.
Portland OR you can go car free. It's not as good as Chicago or NY as far as trains go (still better than most), but the city has 300 miles of bike lanes and the busses are solid.