You can set a default query text coming from am other data source. This case is particularly useful when you want to put a search box Web Part on the front page redirecting to an other page with the same query. Use the query string parameter 'q' from the built-in 'Page Environment' data source.
The search box supports by default query suggestions from SharePoint search. Refer to the following article to know how to add query suggestions in your SharePoint tenant (caution: it can take up to 24h for changes to take effect). You can also add your own custom suggestions providers using following this procedure.
Send the query to a new page
Sends the search query text to a new page. On that page, use an other search box Web Part configured with a dynamic data source as the default query. This Web Part uses the URL fragment '#' to pass the entered keywords. Make sure you use this data source property in your targeted components to retrieve the query.
The placeholder text to display in the search box.