A first-person narrative is an story or opinion that has

A first-person narrative is an  story or opinion that has a speaker evident. You, the author, express yourself as you wish, taking care to support your opinions and facts with evidence and specifics — and, when called for, outside reference.

For example, if one is writing a review of a product or restaurant, perhaps a glance at Yelp will provide support.  Be sure, always, to CITE and REFERENCE any external sources.