Which web technology[ies] should I learn?

Hey guys,

I have never done any web development but am very interested in learning some web technologies. I believe I have a fairly solid understanding about programming, so I think picking up different languages/technologies shouldn't be too difficult. I am a junior in college, majoring in CS, and would like to work on a couple of small projects on the side. One of the first ideas I'd like to work on is a web app (game), where you join a room and play a simple game (roll a dice, do something, wait till your next turn -- repeat until there is a winner). Basically, my question is what technologies should I learn that will help me implement this idea in the best and most easy way?

Thanks!