Hi Steve,
For the front page, consider compressing the served image. This can be done w/ an optimization plugin for images. Consider serving them through a CDN as well.
As for the rest, you’ll need a caching/optimization plugin to improve how your site serves the assets.
For starters, try to minify and merge CSS (and JS but this can sometimes break the site’s front end functionalities).
You then check for scripts that you can defer or lazy load like the YouTube embedded player.
Try preloading your fonts as well as it’s also getting flagged by Google PSI.