Complex sentence: Paris was the place to be, and the capital of the art world, any artist that wanted to be recognized, at that time, was required to have exhibited in a Salon, or gone to school in France.
Split into simpler sentences: Paris was the place to be and the capital of the art world. Any artist who wanted to be recognized, at that time, was required to have exhibited in a Salon, or to have gone to school in France.