Hi Shannon,
Which page do you want to hide the navigation on? You'll need to open up developer tools and find the collection id for that page. (It's in the list of body classes and looks like: collection-5d978ee6590a832f3c3fe6d4)
Then you could do something like:
#collection-id #topNav{
display:none;
}
If you want to remove the whole sidebar it would be:
#collection-id {
#headerWrapper{
display:none;
}
.header-position-fixed-left #pageWrapper{
margin-left:0px;
max-width: unset;
}
}
This would all go into your Custom CSS.