TTFTB slow

[JeroenVdb]

I guess the slow TTFB is related to Wordpress generating the webpage on-the-fly each time someone visits your website. So the speed of your site are primarily dependant on [1] the build quality of the template you are using (or Wordpress in total) and [2] the hardware (processing power to build the webpage) Vidahost is using.

[1] the template loads 23+ CSS and JS files. Some can probably be eliminated. If you do have some technical skills maybe you can edit the template and remove unused CSS and JS files.
Downloading all those files separately also has a performance impact. You can concatenate all those files to one file (I guess WP has some plugins for that) or use the Vidahost Let's Encrypt SSL Support and go HTTPS + HTTP/2 (if Vidahost supports this) which more efficiently handles multiple files download.

[2] Find yourself a Wordpress Caching plugin so the pages don't have to be generated every time someone visits a page. Your TTFB will be (blazing) fast