When you select "+ Story" in the right-hand menu of the Story Listing (see Twine Navigation under Creating a Basic Twine Story), you will be prompted to give your new story a title. You can always change your title later. After giving your story a title, you will be directed to the new Passages View for your story. The page will open with one "Untitled Passage" square in the main Story Map window.
The green circle with a rocket icon on the top left corner of the passage indicates that this is the starting passage for your story. Starting Passages are important because they start your story and can provide introductory information. If you hover your mouse over the passage square, a menu appears with options to delete (trash can), edit (pencil), and play (triangle) your passage.
If you select the three dots in this menu, you will have options to make any passage the starting passage ("Start Story Here") and to change how much of your passage you see in the Story Map.
To edit the passage, hover over the passage and select the pencil. You can also double-click the passage.
This will open a new passage window. In this window, you can give the passage a title, apply tags, and enter the text you want to appear for your readers. An important tip is to give each passage a unique and descriptive title. This title not only acts as a title for each passage, but it is also how you will link to other passages (See Adding Links under Creating a Basic Twine Story).
Tags are useful to help you organize passages that might have common themes or threads. Any term can be a tag, and passages can have zero, one, or many tags. Once a tag is created, you can apply a color to it that will be visible in your Story Map view.
Enter the text for your story that you want your readers to encounter at this point of the story.
There are some key formatting options for your story text. When there is no text in the window, Twine provides a short guide showing the most popular markup formatting options. The simplest and most widely used options allow you to give emphasis to your text and link to other passages. Below are some commonly used formatting options, including:
Click the top right "X" to exit the passage window.
To test how your passage looks, select "Test" or "Play" along the bottom right of the Passages View menu. Both buttons will open a new browser tab and show you how your Story will look and function for your readers. Play will show the experience as your readers will experience it; Test will let you see your source material and highlight any errors. Close out of this new Test or Play tab when you are done.
After editing your first passage, you can add more passages from the Passages View. You can add as many passages as needed to tell the story in the way you want.
To add a new passage, select "+ Passage" on the bottom right of the Passages View menu.
You'll see another passage square appear titled "Untitled 
Passage". You can select the passage square to edit it like described above.
See Adding Links under Creating a Basic Twine Story to start connecting your passages.
Your work automatically saves as you make changes, but how it saves depends on whether you are using the online or downloaded version of Twine. There are important considerations about saving and backing up your work, so please see the Saving and Sharing tab before you start to ensure you do not lose any progress.