Fix and upgrade my WordPress site

We are seeking a highly skilled WordPress developer to fix and upgrade our website, located at https://memoriadeabril.com/. We are experiencing a range of issues with the site and require immediate attention to resolve them. We do not require any new features or functionality added to the site, but rather a clean-up of the current issues.

The ideal candidate will have the following skills and experience:

Proficient in WordPress development, with a deep understanding of the platform's architecture and capabilities
Knowledgeable in website optimization and speed improvement techniques, and able to implement them effectively

Experienced in troubleshooting and resolving website issues, with a proven track record of successful resolutions

Detail-oriented and able to provide clean and efficient code

Effective communicator, able to provide regular updates on project progress and work collaboratively with our team

Here are the issues I want to work :

1- Upgrade the site stack PHP/mysql/wp/plugins, etc.. to the latest version available or supported by my site's plugins and fix any problem related to this upgrade.
2- Verify error logs files and fix reported problems
3- Verify and fix security issues
4- Identify and repair speed issue
5- Complete website audit
6- Improve website security
7- Validate the site with https://validator.w3.org/ and fix all reported problems
8- Deliver all code to our DevOps account when done
9- Conduct a one-on-one screen share conference before starting to ensure mutual understanding of project goals

The preferred deadline for this project is 1-2 weeks.