If I were just starting SEO today, this is one of the first free tools I would install. It's called detailed and it's hands down one of my favorite Chrome extensions. So take something like a simple Denver plumbing website.
I just hit the little d and then I get all of this detail. I can see the title tag, the meta description. I really like the word count.
Give me a sense of how many words are on this page. And click up here and I can see all of the headings on the page. So you can see right out of the gates, that's not a very good H1.
I can see all the different H2s on the page and the different headings on the page. Some of these are not very good at all. I love to look at the images.
You can see that so many of the images are missing. The alt tags, internal links versus external links. I can see all of those on the page.
The social sharing image for the page. So if this page was shared, then you'd see this image and tons of other details. It's simple, it's free, and it's one of those tools that makes quick SEO checks way easier.