There are 3 ways you can search. One using the new tab page (which you turned off), and the others are using the search bar in the upper right hand corner of Firefox and finally you can use the address bar to search as well.

If you use the "grid" button in the upper-right corner of the new tab page, which says Hide the new tab page on hover, you will be hiding the entire page including the search container.

You can also consider to set the new tab page to the built-in about:home page (i.e. the default home page) or another website to get that page when you open a new tab if you do not ant the about:newtab page with the thumbnails.

See this article about the New Tab page (about:newtab):

• https://support.mozilla.org/kb/new-tab-page-show-hide-and-customize-top-sites

You can set the new tab page via the browser.newtab.url pref on the about:config page.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config