Resources to improve your search engine ranking
SEO isn’t only about code-related changes. It is also heavily dependent on link building and social media activity. Moz (among others) provides lots of great resources to learn more about SEO to help your with your SEO strategy.
Another good tool to use is Google Search Console (Webmaster Tools). It will tell you how Google sees your website. Read the how to add the GSC verification tag knowledge base article for setup instructions.