What server should I start legit playing?

[devilsknite1]

Or just be smart and uninstall Graal PC...
But in all seriousness, it depends on what community you're into. Era = young kids crying/trolling all day and you will pretty much be guaranteed to not get anywhere and will get no help; Zod = pretty fun, decent community that's fairly nice and helpful, actual content, fairly easy to grasp (if you actually try to) and a wiki; UN = laid back community, practically all player-based with content and events/mini games; N-Pulse as of now doesn't really have a whole lot of content, but they're making a come back. As far as Classic goes, I was never a fan of its original for PC, but they're definitely worth checking out. Or you could just play all of them and see which ones you like the most.