Vagabond Johnny is a discovery sidequests in Chapter 9, "The Town That Never Sleeps", in Final Fantasy VII Remake, taking place in Wall Market. While heading to Corneo's Mansion, Cloud Strife spots Johnny running.
After seeing Johnny, follow him to the Honeybee Inn in the northwest end of Wall Market and talk to him. Choose to agree or disagree with Johnny, which will progress the cutscene and complete the quest. The choice will slightly affect the questline during the chapter later.