Is it better to activate a 1 Month Gold Account Medal on the first of the month? Or, if I activate it on May 15, will it go until June 15?

It will give you one month exactly from the time and date that you activate it. If you activate it now, you will get 4 weeks, which is a month. :)

Thank yooooou!

If you want to extend your Gold Account time, you can also activate a medal WHILE your current medal still has time on it. If you do, that time will just be added on. Say, for instance, your GA will expire in a week, and you want to renew it. You can activate the new medal, and you'll have 5 weeks of GA time: the week left from the first time, and all the 4 weeks of the new time.