@slappcoding, Please read the Welcome to the Grav CMS Community Forums post. It will provide some guidelines as to what information should be provided in a question.
The more clear the question, the higher the chance you’ll get an answer…
I searched for any videos that would show how to build a Grav site from a theme and could only find one, in which a man called Ravi Sagar shows how to do it.
A link to the video might be handy
and the Quark theme that he demonstrates has changed
Quark hasn’t changed much over the last 5 years. Mostly bug fixes, but not much with respect to functionality or layout.
and there is a new module called Gallery available
What Gallery are you talking about?
Please assume that I am not a technical user who knows how to tinker with CSS, HTML and PHP. I just want to set up a simple site like one would normally do in a CMS.
Please now that Grav has not been build with non-technical users in mind. Grav does not come with a so called drag & drop Page Builder. If the theme lacks some functionality, layout and/or look&feel which your site requires, you will sooner or later need to know about scss/css, Twig and possibly even PHP.
If that’s too much of a hurdle, you might consider looking at tools like Wix and the likes.