The checklist
- Search Console set up, with the sitemap submitted.
- The Pages report shows your important pages as indexed.
- Nothing important blocked in robots.txt or marked noindex.
- HTTPS on every page, with one version of the domain (with or without www).
- Fast loading on a phone; check with Google's PageSpeed Insights.
- Old URLs redirected to their new pages.
- No broken internal links.
- Your business details marked up with schema.
What to fix first
Anything that stops a page being indexed, because nothing else matters for that page until it's fixed. Then speed on phones. Then the rest.
Questions
Do I need technical SEO services?
For a small site, a one-time check and fixes usually cover it. Larger sites need ongoing attention.
How do I know if Google has indexed a page?
Use the URL inspection tool in Search Console.
Is technical SEO the same as site speed?
Speed is one part of it. Indexing problems matter more.