I only skimmed this article but I didn't see any step where the default credentials ("pi"/"raspberry", IIRC) are changed so if you follow this guide you should

I only skimmed this article but I didn't see any step where the default credentials ("pi"/"raspberry", IIRC) are changed so if you follow this guide you should expect your "home server" to be hacked and become part of a botnet shortly after you > head to your router settings and port forward 80, 443, 22 and any other ports that you might want.