The simplest way is to use the paragraph's Number list property (choose Bullets and Numbering from the Paragraph panel's flyout menu).
In that case you don't key in the number or tab separating the number and the text. Like this where I have set a left indent large enough to clear a double digit number and then made the First Line Indent the negative of the Left Indent. When you use Bullets and Numbering the list numbers are added automatically:
