There are many circles that are generalized. Find people that are looking to find people. Some may have common interests and some might be a targeted audience. I find the best way to search in by using the “Home” or “Circles” tabs located on the left side of your Google+ page.

Within the Google Search Bar start typing “Public Circles”. Halfway through you will be given suggestions below the search bar. Here there are hundreds of people to choose from. Another way to target what you are looking for. It is in your best interest to read all the profiles and follow only what really pertains to you, there is that many to pick from.