To add a search box to your space, there are two macros that you can choose from. Additional information for each macro is below each description.

Livesearch Macro

Livesearch: shows search result keystroke by keystroke, as the user is entering the search term.
Example: {livesearch:spaceKey=xxxxxx}, where xxxxxx=the key for your space.

Screenshot: The Livesearch Macro in Confluence

Learn how to add the livesearch macro to your site.