You cannot use C/C++ or any such language that requires compilation on your website.
HTML is just a markup language that displays the contents of your page on the browser. You set the styles of your page with the help of CSS. The page is made dynamic with the help of scripts i.e. JavaScript and jQuery (this means the page contents can be changed on run-time). You can connect your webpage to the server on run-time with the help of a server side language such as PHP or Ajax etc. You can store contents into databases using SQL. Learning these languages does NOT cost anything. You can learn them from the internet for free.
One of the best websites to learn all these languages is:
http://www.w3schools.com
To learn HTML: http://www.w3schools.com/html
To learn HTML5: http://www.w3schools.com/html5
To learn CSS: http://www.w3schools.com/css
To learn CSS3: http://www.w3schools.com/css3
To learn JavaScript: http://www.w3schools.com/js
To learn jQuery: http://www.w3schools.com/jquery
To learn PHP: http://www.w3schools.com/php
To learn SQL: http://www.w3schools.com/sql
To learn Ajax: http://www.w3schools.com/ajax
There are loads of examples with each tutorial to illustrate everything. Hope you enjoy learning from these sites.