About the space between your site logo and blog header, you have to modify the padding pixel from your template custom css file, you can check my attached screenshot below.

Regarding with your blog header title and description font format, you can try applying the following CSS :

/*  This css for title */

body #eb .eb-brand-name {

    font-family: 'Lato', sans-serif !important;

    font-size: 16px !important;   

}



/*  This css for description */

body #eb .eb-brand-bio {

    font-family: 'Lato', sans-serif !important;

    font-size: 16px !important;   

}