Of course it will still take a couple of years before you are ready to choose your profession.
Nevertheless, it is useful to experience what a certain profession really implies at this moment in your education. Therefore, you are going to join someone you know for a day or part of a day. This can be for example a relative or an acquaintance. It is not necessary to find someone with a profession that you would like to have yourself later on life. You could ask anyone with a profession that you would like to know more about.
As a matter of fact, your internship is all about taking the first steps into the world of work..