You can find line spacing in Word in the Home tab, under the Paragraph group.

To change the line spacing for a paragraph or group of paragraphs:

1. Select the paragraph or paragraphs that you want to change.
2. In the Home tab, under the Paragraph group, click the Line and Paragraph Spacing button.
3. In the Line and Paragraph Spacing dialog box, under Spacing, select the desired line spacing option.
4. Click OK.

To change the line spacing for the entire document:

1. Click the Design tab.
2. In the Page Setup group, click the Paragraph Spacing button.
3. In the Paragraph Spacing dialog box, under Default, select the desired line spacing option.
4. Click OK.