Post in Germany Hamburg St. Pauli

Hey there I am a Spanish retired grandmother learning german and wanting to go to Hamburg to study from the end of july till the end of august. I would like to find a place to stay around Altona, Ottensen mainly but somewhere round there as my son and family live in that area. Does anybody know of a possible hosting place?. Obviously I am paying for the stay, and would love to share it with a woman in a nice neighborhood.