I'd start by correcting the 8 errors https://validator.w3.org/nu/?doc=https%3A%2F%2Fbegold.eu%2F found.
As to SEO, that area is something well done. But make your site code perfect would be my first step.
Analyse your website via Google Analytics tool
First analyse your site fully with help of some tool.
I couldn't connect to your site. Is it working??
Check your website is working right now. Anyway optimize your site via Google Analytics.
I couldn't reach your site. Please refer few SEO tools freely available in Google, that will definitely help you.