Yes. Start in slowly, do 3 minutes and build up each week. A heart monitor would be good if you want to do aerobic sessions. Subtract your age from 180 and aim for that pulse rate, it just exercises the heart and lungs which are the basis of all fitness. Do that for a while before you do any strength training. Health will also depend on what you eat and drink.
rowing is good for the large muscles in legs and arms too but will you stick to it.... if you have the machine already fine but think before buying expensive kit