When I check your site with Pingdom I notice it takes over 5 seconds just waiting for your server to respond to it. There are definitely things you can do to speed up your site by using a caching plugin but I think that initial delay may be a hosting issue. Perhaps someone more familiar with hosting problems could verify or offer some more advice on how to fix that in particular.
You can also try https://developers.google.com/speed/pagespeed/?hl=de
It will give you tips on what you need to optimize to get a better page speed. However, the delay seems to be a hoster problem, as jtleathers pointed out.
I have spoken to the host and they are saying there is not a problem at there end.
Luke
(@danceyrselfclean_admin)
There might not actually be any problems with your hosts server, but if they are a budget shared hosting provider then they are likely to be overloaded and slow to load due to the limited resources.