I would suggest you to list all your requirements. After you are done with the requirements you can select what suits you the best. Current web applications use a cocktail of several technologies. The choice of technology should be purely based on your requirements, ease of use and budget constraints.
Of course, you have a plethora of several open source technologies to help you out. Biggies such as Facebook, Google too use open source. Since you are a student go for open source technologies.
This is a good link if you want to learn web from scratch : http://www.w3schools.com/
Thanks