I'd recommend starting with either C++ or Java. Lua is more of a scripting language than a programming language, so it works a bit differently. Java is what Minecraft mods are coded in, so it makes sense to start with that, if modding is what you're aiming for. Feel free to ask in the direwolf20 IRC, too. Usually someone can help. But don't ask in the forge IRC channel. Lex will tear you apart