There are many things a developer can do to improve loading speeds, your webpage loading speed is related both to the bandwidth provided by your hosting provider and the data downloaded by the user upon reaching the content on your website.
Your website provably loads slow because of the large image files such as the background image which is sized 366kb and some other images on that page.
The last thing to consider is the client's internet connection speed but it's not related to the work on your server and website.
This is because your website was loaded over HTTPS, but want to load also an insecure stylesheet 'http://www.w3schools.com/lib/w3.css' wich must be served over HTTPS too. The blocking is responsible for long loading in my case.