You don’t even need to go hardcore and use advanced concepts, if you only do simple stuff like you mentioned, ditching for loops, taking advantage of reducing functions and have consts assignments you will see a great improvement in code quality, IMHO.
Functional programming is definitely worth learning. It will make you a much better developer. What I’m advocating here is to apply JEFP (Just Enough Functional Programming) to deliver working, maintainable software without forcing yourself to achieve 100% purely functional solutions.
Web-fonts are a great way to create a distinctive look for your website. Choosing a custom font is not a bad idea, but keep in mind that it also adds to the weight and loading time of your site. Sometimes — on opening a new website — you might see a sudden change of font-style right after the page has loaded. This happens because the browser already paints the document with the default (fallback) font, and then has to re-paint the DOM (Document Object Model) once the desired web-font is downloaded. Don’t be afraid of using common font-families (Arial is a great example). Adding a web-font does not magically make your website look better. The quality of your content is by far more important. When considering using a web-font, my advice is to contemplate if the use of the font is worth the sacrifice in performance.