change font, delete gray box

Hello,
about the site-description:

.site-description {
  color: black;
  font-family: Opensans;
}

something like the CSS above doesn’t work?
Slider caption background:

.carousel-caption {
    background: none;
    filter: none;
}

For all other things:
general guide -> https://doc.presscustomizr.com/customizr/
how to inspect pages to understand which selector you need -> https://doc.presscustomizr.com/customizr/browsers-dev-tools/

Hope this helps.

Hello!
I actually had to change

.lead {
font-family:"Alegreya";
font-weight: 600;
}

to make same font as in .site-description
because Polish special characters were displayed little ‘skinny’ in .lead sclector.
Thank You very much for help.

oh forgot to attach to better understand my problem
https://postimg.org/image/z6ue4wzv9/

Oh I see now what you meant ??
Sorry I didn’t really get it.
Glad you solved!