Sorry for the late response!
@MRQ Oh, right, I meant making an engine for the game, not a game engine that can be used to build any kind of game. But I think even doing so takes so long >_<
@Eck Yeah, it's my first time trying to make a good game, I've made a maze game 5 or 6 years ago using Game Maker but that wasn't a good thing :(
And also you are right, it happened to me a lot that writing a program without knowing the framework or tool caused in a messed up code and headache. Thank you so much for the link. Isn't Irrlicht only used for 3D stuff?
@ninnghazad I have no problem in implementing the networking (not multiplayer! just using sockets and how to manage them, like in a upload/download or chat application, I've never implemented multiplayer but it should be easy as it's just about sending small amounts of data and receiving them back, server handles all of those ...)
Also the game I want to make is a RPG open world game, which users can run their own deidcated servers and have their own map, levels, missions, etc and everything is scriptable using Lua or AngelScript. If you have ever used SA-MP or MTA, you should have an idea how it should look like! The only things that I have to implement are these:
Loading and managing resources, rendering stuff, embedding Lua or maybe AngelScript, multiplayer and networking base so users can download content whenever they connect to a server, APIs for having access to the game from Lua. So if you sum it all up, it will be like a framework that players have to make their own game logic and content in a scripting language. So the game itself is nothing but a renderer and resource manager! That's all about it.
But as you guys adviced, I should start making something smaller and easier without multiplayer and add more features to it.