Is pretty hard to make big games, you need to know a lot of C++.Try to make small applications to understand the way and steps to produce a simple game.

You do not need to know C++ to make a web based game.

You should make a game that you love to make. Making a web-based game is not very difficult, but you still need determination and time to learn a lot of new stuff and implement it. Only if you love the game idea, will you make the time to work on it. What you can do is start with the basics like the login-registration pages, but keep it focused on your game. Start working on your dream game, but cut down the features for a start and start implementing modules. Once you get the hang of how things work out, then keep building on it.

There are plenty of tutorials available for building web based games. Try to find them or I will post them later.