Being prototypical means representing the usual or quintessential version of something. The prototypical example of a superhero, for example, is a strong person who wears a cape.
While the adjective prototypical can be used for things that are literal prototypes, or original samples that later versions are based on, it's usually a near-synonym for typical. So you might say that you live in a prototypical suburban neighborhood, much like every other suburban neighborhood, or that you behave as a prototypical oldest child, with all the common personality traits they tend to have.