Logo and Menu

I am working a site using the Estate Theme and I want to center my menu. I also want to add a logo image or header image(only on home page) but I want the image to expand and contract with the window as you make it smaller or larger. I want no white space to show on the sides. right now my site is on a localhost but the header, menu, and logo is identical to the one on this sites home page https://www.shotbykaren.co.uk/

currently I removed logo white space (area above menu) by using custom css

header#masthead hgroup{
display:none;
}

but my logo comes back if I take that out. Any help is greatly appreciated!!!!