It seems like your website is quite heavy, what you’ll need to do is optimize it. While doing so, you can optimize your server as well.
Have in mind that your website looks quite heavy with all the 3D graphics. I’ve used a couple of third-party tools to check what you can possibly optimize on your website. You can check the result here :
If you click on both links, you’ll notice something really interesting. Your home page is quite big more than 30 MBs. There are other suggestions on how you can speed up your website in the provided links.
Now let’s turn our attention to your server. It seems like you are using Apache. I’ll recommend installing PHP-FPM to use with it alongside maybe Opcache as a server-side caching method. Having said that, the most problematic section would be the optimization of your website - www.vizzio.ai. Please take a look at the provided links and see what further actions you need to take in order to speed it up.