Hello,
I am an experienced website speed optimizer/developer, also doing the same jobs in other freelancers sites.
I will do manually apply internal optimizations to speed up your site using; server side changes, identify the files which taking long time to execute, Database Table/sql optimize,remove unused CSS / JS, compress (images, CSS, JS), Eliminate render-blocking resources, Defer unused CSS, gzip, Leverage browser caching, expire headers and fix the code files which taking long time.
So your site's home page get better score at Google Pagespeed Insights as much as possible.
Give me control panel admin and FTP etc login/pass so I could start work.
Before start work, let's discuss about it.
Not everything is possible but I can advice you a valid reason.
Thanks