Is there a way to make the caption item on the home slider transparent? 

Also, how can I change the font and its attributes?

Unfortunately I can't because it's on a local install. In digging around I pieced together the following code though in the custom CSS that seems to have worked.

body .orbit-wrapper #featured article .post-title h2 span {

color: #fff !important;

font-size: 72px !important;

line-height: 80px !important;

font-family: 'OpenSansLight' !important;

background-color: rgba(40, 43, 48, 0) !important;

box-shadow: 0px 0 0 rgba(255, 255, 255, 0), 0px 0 0 rgba(255, 255, 255, 0);

}

body .orbit-wrapper#featured article .post-title h2 {

margin-top: 50px !important;

}

@media only screen and (max-width : 480px) {

body .orbit-wrapper #featured article .post-title h2 {

margin-top: -50px !important;

}

}