putting menu at bottom of home page

The only problem doing it this way is the margin percentage will need to change based on the amount of content you have on the page. Maybe someone else will have another idea.

.home .main-navigation {
    position: absolute;
    width: 100%;
    text-align: center;
    float: none;
    margin: 60% auto;
}

The best way to do what you want is to edit the header & footer PHP files with if statements, unfortunately I’m not a PHP guy.

Can you move it in the DOM instead? That’ll be much better for everyone, including you as pointed out by batharoy.

What is the DOM and how can I do that?

thank you.

Start by creating a Child Theme: https://codex.www.ads-software.com/Child_Themes

If I create a child theme and make changes there, does it override or negate the Custom CSS changes? Or do both simultaneously apply?

The Child Theme will inherit the parent theme, so any CSS on the parent theme will be inherited via the ‘@import‘ line of code