@TooFriendly112,
When you register on a steam forum your already registered for steam.
However that is like Amazon jail broken mentality.
When you purchase a game that is steam ( even from a local store ) your still buying a game that you have to download that logically "you do not own" but you own the rights to play it on steam and that account that is associated with that game itself, across devices that support steam via your account.
You should be able to log into a steam forum and ask these questions, or even call a number if possible ( as with facebook problems ).
That purchase is more or less a gift-card assigned to a specific product. That is if you did not have to give any personal information in while making the purchase itself.