To add a search bar (for searching within the website) to your WordPress website, login to your WordPress dashboard and proceed as follows:

• From the left hand side pane, select Appearance.
• Click on Widgets.
• Now, the widgets window opens up that lists all the available widgets on your WordPress.
• Browse and locate the widget named Search.
• Click on the widget (Search) and a dropdown menu appears which lists the places where you can place this widget on your website.
• Select one place (Ex. Left Sidebar) from the list by clicking on it.
• Now, click Add Widget button located under the same list, to add it to your website.

(If you do not find Search widget in your widgets, then follow the steps outlined under, “How to add a new widget/plugin to my website?” and then follow the steps mentioned above.)