I recommend you look up David Risley.
My personal blog has over 12 million pageviews but I had to start over (deleted everything) because I was ranking in Google for keywords that made no sense to my core business. For example, I was ranked #1 for "symbols" and "peace symbols" and "heart symbols". I had Fossil and Vans advertising on my blog. (That all started when I wrote a blog post about ASCII art. I was an ANSI/ASCII artist back in the early 90s.) So with SEO, there's a weird luck component.
The lesson is, don't talk about anything you could accidentally become famous for. On the other hand, you might decide to change careers and milk an off-the-wall niche. (Become a professional ASCII artist? It's possible!) In that sense, SEO can lead you unexpected places. Conversely, if you can stay fanatically focused on one topic, that really helps for SEO.
Starting from scratch, I recommend you forget about SEO and focus on social media. Photos help get clicks to your blog via Twitter, Pinterest and LinkedIn. Use hashtags! Go cross-platform. For example, make a blog post into a podcast, make the podcast into a YouTube video, pin the video into Pinterest. If you're syndicated everywhere, you're not so dependent on Google. Google can trainwreck your life, don't get seduced by easy traffic.
But back to David Risley, he says (summarizing) "Your blog is not the business. Your blog is a channel to promote your business."