Hi @EricaFontimedia,
if you really want to optimize your performance you’ll need to dive into theme development and develop your own theme with your desired optimizations or - if you’ve bought a (premium) theme from the marketplace - try contacting the theme developer and ask him for help.
As far as I know there’s no real tool like a WordPress plugin which handles everything “with one button click”.
So if GTMetrix or PageSpeed tells you to improve X you must investigate the cause and solve it independently.
For instance if you’re loading some JS files from an external source, upload those scripts to HubSpot. This will reduce the loading time
best,
Anton