Help me with my new website!

[FlatAssembler]

But because I've programmed the site properly, I will be able to make changes to my (very large) site relatively easily.

Ah, you make it sound so easy. Yes, not using too much inline CSS does solve some problems. But it doesn't do miracles.
The CSS "calc" function resolves many instances where you would otherwise need to use JavaScript, but it wasn't properly supported even in the browser I was using when I was making that website (Safari 6), so I was kind of forced to insert inline CSS from JavaScript to simulate that.
Even so, separating JavaScript and CSS that's used in all pages into separate files wouldn't be an easy task. To make the transparent SVGs on the homepage (the problem appears only because of the background image on the homepage) render properly in both Internet Explorer 11 and other modern browsers, I had to change quite a lot of CSS and even do some browser-sniffing in JavaScript (I gave up trying to make it render correctly in Internet Explorer <=10 and Opera <=14 and just deleted the background image in them).
Also, since I was setting up a mobile theme in JavaScript, I need to delete all the JavaScript-generated SVGs except for those that are somehow related to the text. If I'm going to just include JavaScript from an external file in all my pages, it's not an easy task. I'd have to modify it somehow, and it's not at all obvious how.
Maybe you can do that after 10 years of learning to program. After 6 years, I can't do that.

Don't commit your full efforts into doing things badly.

But if I am trying to learn how to program, it's important to build stuff, rather than just read the tutorials, right? And it's also much better to figure out how to do something myself, no matter how badly, than to just copy somebody else's code I don't even understand, right?

I learned web development by hiring web developers for projects, then learned from them over time.

I must say I am amazed. You've figured out that some program would be useful before knowing basically anything about programming? Tell me more about it! I still have no idea for a project that would be useful and relatively easy to program.

The development goes beyond building the site since you want to control traffic to your site and provide relevant to those who visit.

Well, like I've said, the page on my website that gets by far the most traffic is one about the Croatian Toponyms. I can kind of see why, but it's a mystery to me why my house-selling page isn't getting more.
It's often said that the best way to get people to see your house-selling page is to post it on Facebook in the relevant groups. However, I can't sign up to Facebook under my name, because I got banned from Facebook because of what I was posting about politics.

I've literally copied a sample project that someone had working online, run it in development, and had it fail, and have zero idea at all why.

Yeah, me too. I've tried to make a scientific calculator for Android by letting Duktape execute the JavaScript code identical to one in the web-app. Do I need to tell you how much tweaking I had to do to make it useful? First, I got a bunch of ReferenceErrors because "if (window)", which I've used quite a few times in the code, doesn't quite do what I thought it would do. Then, a bunch of errors related to the global variables not ending up initialized, because I made them get initialized only in button-click event handlers (seriously!). Then, when I finally got it to load without errors, it was very slow. But I managed to speed it up around 7 times just by minifying the JavaScript using jscompress. It's quite ironic that what made it slow weren't the terrible algorithms I've used (there is an algorithm to do something in linear time, but I was using an algorithm that runs in cubic time because it was easier to implement in JavaScript), but the incorrect usage of the framework.