You can use the Rich Content Editor to align text.
The Rich Content Editor is used in features that support the editor (Announcements, Assignments, Discussions, Pages, Quizzes, or Syllabus).
Open Rich Content Editor
Open the Rich Content Editor using one of the Canvas features which support the Editor.
Use the tools on the Rich Content Editor toolbar to align the text. You can set the position of the text on the page with the Left, Center, and Right Alignment tools  or indent the text using the Indent tool .
Click the Save button.
Note: When using the Rich Content Editor in Assignments, Discussions, Pages, and Quizzes, you have the option to Save & Publish. When using the Rich Content Editor in the Syllabus and Discussions pages, the Save button may appear as “Update Syllabus” or “Post Reply”.