Is Ocid The Right Substitute For Rantac?

I am male, 76 years old. I suffer from frozen left shoulder for the last 2 months and feel pain when swiveling my left arm beyond a short arc. Further, for the last several years I find no strength in my both legs at the calf muscles. This weakness is NOT to a serious degree since it does not cause me any problem, pain or discomfort for short walks of 2 to 3 KM at a time. I confess guilty to have been extremely lazy with regard to physical exercise or walking, doing neither for several years, finding comfort in physical inaction beyond usual daily chores. Last week my ortho-specialist found my left shoulder x-ray as Nothing wrong and prescribed me 5 days of [1] DOLOMEX DT 1-0-0 after food and [2] RANTAC 1-0-0 before food. Additionally he prescribed ice fomentation on shoulder 1-1-1 x 5 days and mild active assisted shoulder mobilisation exercise. I am to report back to him after a week. However my medicare agency gave me instead PARACETEMAL and OCID 1-1-1 x 5 days. My question : [1] Since I do not find much pain, will it be OK if I do not take PARACETEMAL at all ? [2] Is OCID the right substitute for the specialist-recommended RANTAC ? [3] Can I redeem my calf muscles if I begin mild exercises from now on ? What kind of exercises ? Will 20 minutes brisk walking a day do ?