Upgrade Site to PHP 8.4 (With Avada Theme Purchased Version)

I need the entire code-base of my website brought up to full compatibility with PHP 8.4. The site currently runs user authentication and a blog, and it relies on several custom plugins that will all need individual attention during the upgrade... (Budget: €8 - €30 EUR, Jobs: HTML, MySQL, PHP, Software Testing, Web Application Audit, Web Development, Website Optimization, WordPress)