If you created a new process from scratch, you will see the following page:
You can start adding new steps by typing them into the New steps input field, then clicking Add button at the end.
You can organize steps into a hierarchy by typing extra spaces before their names. For example:
Hint: You can also press Enter or Shift+Enter in the tree to create new steps/substeps. Press Space or F2 to rename steps right in the tree or Delete to delete a selected step.
It will result in the following tree of steps:
Then, after you added all the steps you planned, you can edit their properties to make them work in a desired way.