The <title> element is the main source of the title link, but Google also uses "the main visual title", headings, prominent text and anchor text, and replaces stuffed or boilerplate titles. That keyword-first titles perform better is unconfirmed. Write one distinct, accurate title per page (Meta Tags That Matter).
The meta description is not a ranking factor: in 2009 Google said "we still don't use the description meta tag in our ranking", and snippets are "primarily created from the page content itself".
Heading order "doesn't matter" to Google, because "the web in general is not valid HTML", and validity itself is unconfirmed as a factor. Keep the <head> valid, though: canonical and hreflang links pushed into the body by a parsing error are ignored. For images, alt text is "the most important attribute", captions and nearby text help, and file names give "very light clues":
<figure>
<img src="/img/dalmatian-puppy-fetch.webp" alt="Dalmatian puppy playing fetch"
width="800" height="533">
<figcaption>Our 10-week-old Dalmatian, Pepper</figcaption>
</figure>Structured data (JSON-LD and schema.org, Microformats) makes pages eligible for rich results; a direct ranking boost is unconfirmed.