Hi Dojode, you can change the default search engine to Bing using the Search panel on the Options page. It's the top control on the page, you don't need to change the controls further down the page. This article should get you there: Change your default search settings in Firefox.

That should take care of the address bar, the search bar, and the search box on the built-in home page.

Success?

Dojode said

I want my homepage to be mozilla firefox.

Hi  Dojode   !
You can set your homepage : 3-bar menu => Options => General When Firefox starts :   'Show your homepage' Home Page :   here's where you paste Mozilla's URL   (the page that you want for your home page)

Hi again, Dojode   !
As I only answered the second half of your question, and 'jscher2000' answered the first half   (which is also the header of your question),   I think that 'jscher2000's ' answer should be marked   'Chosen Solution'   .......