To start, I just used google maps to find walks around my neighbourhood long enough. I then started going by my watch and caring less about distance. I started hiking again after a few months, after a long hiatus. Small walks to start, an hour or so on a Saturday. I bought a cheap gps watch on run-out clearance mid year, to help me track miles as a friend and I set a large goal. Pen and paper could have given the same metrics though.