The Apple Support Communities are an international user to user technical support forum. As a man from Mexico my first language is Spanish. I do not speak English, however I do write in English with the aid of the Mac OS X spelling and grammar checks. I also live in a culture perhaps very very different from your own. When offering advice in the ASC, my comments are not meant to be anything more than helpful and certainly not to be taken as insults.
Try to buy an app and you will be presented with a screen to create an iTunes/Mac App Store account if you have never created one. If you have an iTunes account, sign into the Mac App Store with the same username and password.