There are following SEO Errors or basic seo mistakes for website
1. The site's speed is slow.
2. Google reviews are negative.
3. Faulty Google Verification Code for My Company.
4. There are no location-specific pages.
5. Content that is duplicated.
6. Images are broken and alternative text is missing.
7. The site's content and information are out of date.
8. Your website is not mobile-friendly.
9. 404 page is not available.
10. Canonical URL is not available in website.