Make improvements to the audit on Modx

Hello
It is necessary to make improvements to the audit on Modx on a 3-page site

Edits of this nature:
- fix errors in HTML
- Images with an empty alt
- Images with an empty title
- Speed optimization for mobile devices
- Speed optimization for personal computers
- 404 Error Page Design
- Broken link
- add canonical URLs
- update meta tags
- update the date of the pages in the sitemap file
- Implement Product markup on the site

I will send a link in a personal message, please estimate the approximate cost and terms