Open the Stories tab at the bottom of the page.
For text-based stories, select the icon, select a background color scheme you'd like the story to follow (this is optional, you can stick to the default color), and type the text. You can also change the font by selecting the icon. Click to post the story.
To take a photo/video and upload a story, select the icon, capture the photo/video, and add a caption to the story by typing it into the bar at the bottom. You can crop images by clicking the icon and trim videos using the trimming bar above the video. Click to post the story.
To upload an existing photo/video as a story, select the icon on the stories page, click the box on the bottom left that will take you to your gallery, and select the desired image/video. You can crop images by clicking the icon and trim videos using the trimming bar above the video. Add a caption to the story by typing one into the bar at the bottom. Click to post the story.