Any of several languages would fit that bill, including PHP, Ruby, Python, Java, JavaScript, C# and others. As important as choosing a language is selecting a web framework and also learning how to build a web application.

For a novice, I would recommend the free "Engineering Software as a Service" course[1], which uses the Ruby language and the Rails framework to teach the fundamentals of web development.

[1] https://www.edx.org/course/uc-berkeleyx/uc-berkeleyx-cs169-1...