I want to insert my photo as background in my video which has white background
To replace a white background with an image, you need to use a Luma Key.  A Luma Key is like a Chroma Key, except that instead of using a color value (such as green or blue, usually qualified also by a certain level of luma), you will use only a luma value (such as anything brighter than 200 IRE).

Most NLE software have both compositing and keying functionality.  But now that you know what the effect is called, you can research how to access that functionality in the software you are using (or will use).