How do you get a BitCoin Wallet?/ How do you determine what your wallet code is?

Hello. I've been trying to set up a BitCoin wallet for quite some time now, but am unable—despite reading the many so-called guides (which are a bit too complex for new inexperienced users)—to figure out how to set up and configure an offline wallet. I have downloaded the latest version of QT-BitCoin and installed it, not to mention waiting for it to store ~"170 years’ worth" of transactions on my computer. Now that it is completely done installing and "synchronizing," I can't even find out what my wallet code is. Has merely installing the program created the wallet for me or do I need to register the program with a website? If I already have a wallet, how do I know what the wallet code even is?