Its not a hard job to build a site . The basic is you need to know any of these language php,asp .net,js,XML,…ext .and HTML is basic to all these. To decorate your site you need to do some CSS work . if you know photoshop then it will be very easy .
After building your site if you need to view it mobile you should need to add bootstrap . then you need to host your site to view the site in internet .
If you found its very hard then try blogging . its very simple and free !!