It was much easier than it looked. So, the issue was my internet connection. I don't know what exactly has happened, but something was blocking Android Studio's access to Google and others necessary services. As soon as I tried to open Android Studio via my mobile Internet, everything has worked properly! I wont delete this in case somebody has the same issue. Hey, bro, i had the same problem as you probably have now. Just try to do the same thing with another wi-fi. Love everybody! :)