PHP Application Upgrade and Fix (Easy Project)

I need a qualified PHP developer to upgrade an old PHP 5.4 website builder application that is currently not functioning due to a database connection issue. The server is currently running on PHP 8.4, and the database is using MySQL 8.x.

Requirements:
- Upgrade the application to work with PHP 8.4
- Fix the mysql_connect error preventing database connection
- Restore functionalities that are currently not working, specifically:
- User login system
- Content management system

Ideal skills and experience:
- Strong expertise in PHP, especially in upgrading legacy applications
- Proficient in MySQL and database connection issues
- Experience with user authentication and content management systems
- Ability to troubleshoot and fix existing application features

I will provide the entire application and database to the chosen professional. Please review the attached error screenshots for additional context.