If you have Motion, create a new Title project. Then, just save it as Basic Paragraph or something like that.
The initial default text in a startup Title project is in Paragraph Layout format. It's set up as a lower third, so if you're familiar enough with Motion, you can customize the starting position.
The text in FCPX will be fully editable, including setting margins and tabs (and length, etc. although text will go on "forever" regardless of the length setting.)
If you don't have Motion, you can download a "basic text" title in paragraph layout format here:
http://sight-creations.com/fxexchange/Paragraph%20BasicNoBG.zip
The background (Title Background) has been turned off so that you can apply opacity fades to the title without affecting the storyline media.
If you don't know about the Ruler, and don't see one when you apply the title and double click on the text in the *viewer*, there is a small icon in the upper right corner of the viewer that will toggle the ruler. (It should be on by default.)
HTH