... but took two years to reach. HTML is at its core, one standard. It is progressing up the ladder with technology advances by adding newer recommendations, this release being the latest. One cannot stress enough the importance of treating HTML as a whole, not an iteration. The new does not replace the old, only add to it.
It will take a year or more to read the whole W3C site, but if you glom on to the main parts, HTML in general and work up through HTML 4 and beyond you will get the full picture, especially the why's and what-for's. Same with CSS. Equality important read, and W3C.org is where to start.
Ads and plugins are another thing altogether, since they are largely out of our control. For a new site I would stay away from both for the first year and focus on content creation. The site will do fine if kept up, and the numbers will be there when it comes to selling advertising. The more links that point to a site before it has advertising the better.
Back to quick load times. How do we do it? Well, we discussed media queries. That's a shoe-in, for sure. With them we can not only select the correct resolution of images to send down, but also the number. The technology is there to only send down what reaches or is just below the fold. You'll see lots of sites doing this now. Content only comes down if the user has scrolled to that point in the page. This means longer pages are no longer an issue. However, in absence of that support on your site, it means using smaller pages to start the initial download of the site. A short and simple index page with all the navigation and applicable hot spots and textual content is the optimum way to start the ball rolling.
No more than 600 words, a limited number of images apart from skins and fully crawlable navigation to every other landing page on the site that may apply. These pages will lead to the deeper, richer content if the user sniffs them out. Then the speed and size rules change, a little. Someone who is engaged will wait. They landed and engaged, so they are marginally committed at that point. I think you get what I mean.
There are practical approaches right from the get go, without bringing on a whole plethora of other supports. HTML and CSS by themselves are a dynamic duo. Don't spare them any expense in your learning path and as you progress to other areas of the stack, keep them front and center, always. You'll thank yourself three years from now.
You're welcome. Happy coding!