Looking to increase the speed on two of my Wordpress websites

Hey everyone, I currently have two Wordpress websites that use the same theme and I need the speed to be DRAMATICALLY increased. I'm getting load times of around 40 seconds and a score of E on GTMetrix.

I'll need you to use any techniques you know of, possibly download used images and compress them, take out any bulk in the theme, use a CDN if needed and install any plugins that will help us

Looking for a real pro on this kind of thing here as I need these load times down to a couple of seconds and need this done ASAP please. Both websites are pretty much the same right now just branded differently so the process can be duplicated.

Thanks!