Hi there,
i had a quick look – there is a slow FCP time, which ideally is what should be tackled first as any improvements made here will trickle down to all other metrics.
Things i see:
1. A number of fonts are being preloaded. Thoughts:
Can the number of fonts be minimised.
May be better to set a font-display rule for a fallback font instead of preloading.
2. Requests to amazon servers. Adding a preconnect for those URLS may reduce the DNS lookup time later in the load.
3. Theres a bunch of JS files being requested up front without optimization.
The best way to see what is causing the biggest issues is to open the site in Chrome, open Dev Tools, and on network tab Disable Cache and change Online to Slow 3g. With the dev tools open, refresh the page and check the waterfall report.