The following steps are adapted form Esri's StoryMaps website. For more details visit this website: https://www.esri.com/en-us/arcgis/products/arcgis-storymaps/resources.
Go to the StoryMaps.com website to create a StoryMaps account. You can also find a wealth of resources and tips for creating StoryMaps on the website, including links to video tutorials like the one below.