Hello,

Regarding your query related to uploading logo, actually theme defines the section(height & width) to display the logo in the site. so, there will be no effect in the size of logo even if you have used large size of image.

Also, if you want to increase the size of logo in the site then you can add following given CSS code in Additional CSS section by going to Admin Panel > Appearance > Customize > Additional CSS

@media screen and (min-width: 567px){
 .site-logo img {
    max-height: 100px;
 }
}

Regarding your query related to ‘website to look exactly like this one’, actually, the theme you have used is ‘REBLOG’ theme and the demo page you have mentioned is of ‘Power Blog’ theme. So, the site created using ‘REBLOG’ theme cannot be modified as the demo page of ‘Power Blog’ theme.

If you have any queries further, let us know.

Thank you.