Website page speed, fix all issues and rank my website

To give you an example: I ran a site analysis on GTmetrix and the is the result:
performance 51%
structure 65%
LCP 1.6s
TBT 271ms and CLS 0.56 a
Fully Loaded Tim - 4.4s
Remove unwanted plugging, install relevant plugging, configure recently purchased and installed WP Rocket.
Fix any broken pages and errors etc. Rest I leave it with you to diagnose and make recommendations as an expert.
I also attached some screenshots for your consideration.

Before I accept a proposal, I need to know that you will investigate any issues with the site and provide me with a diagnosis, recommendations, limitations, timeline and cost.
I seek an expert developer to perform a comprehensive website performance assessment and optimization project for my WordPress site. The site currently suffers from slow page speeds which require investigation and remedy. Preliminary measures including installation of a caching plugin have been undertaken but the cache is not appearing as intended. A full audit is needed to thoroughly diagnose specific technical issues hampering performance.

The selected developer will backup the site and commence a detailed technical review and testing. All facets impacting page load times and user experience will be evaluated and remediated as necessary. This may include tweaking and streamlining code, database optimization, image compression, cache configuration, browser caching directives and more. Optimizing the site's infrastructure and deployment settings for maximum efficiency is also important.

Upon completion of optimizations, a report detailing the work performed, metrics measured both before and after including page speed scores, resource sizes, number of queries and more will be provided. The overall aim is to have site performance and search rankings improved through resolving current technical defects. The developer must have extensive WordPress experience particularly with performance tuning. Please provide your hourly rate and anticipated timeline to complete this project to the high standards expected.