Caption fonts disappearing

(Was “Third question, no replies,” but realized that was obnoxious. Sorry; I’ve been sitting at the computer for three full days and I’m right back where I started.)

Can someone please help me? I’m running into one problem after another, and it’s only getting worse. I’m sure these are very basic issues, but I’m completely beside myself at this point.

I’ve been struggling just to create a home page with a large feature image with a title and tagline text (no logo). I finally did a fullscreen slider with one image and caption text – not ideal, but it seemed to work. But I can’t get the fonts I want. (They’re installed.) I can get them to show up after many attempts and many purges, but the minute I make a change to pretty much anything, the fonts revert and I can’t get them back. I’ve tried over a dozen css excerpts I’ve found, in many searches. The only combination that got things anything close to the way I wanted them is below – but they disappear whenever I change anything else related to headers, fonts or menus.

#fullscreen_slider_1 .avia-caption-content p {
font-family: ‘cinzel’, serif!important;
}
.avia-caption-title, .avia-caption-content, .avia-slideshow-button {
-webkit-animation: 0s ease 0s normal none 1 running none !important;
animation: 0s ease 0s normal none 1 running none !important;
visibility: visible !important;
}
#top #wrap_all .slideshow_caption h2.avia-caption-title, #top #wrap_all .av-slideshow-caption h2.avia-caption-title {
font-family: ‘rock-salt’, cursive!important;
}

#top #header .av-main-nav > li > a .avia-menu-text, #top #header .av-main-nav > li > a .avia-menu-subtext {
color: #000000!important;
}
.avia-caption-content {
font-size: 18px;
background-color: rgba(0, 0, 0.2, 0.2);
width: 600px;
}
.logo { display: none; }