Just for a bit more clarity, every class advancement quest gives you a free level.
5 -> 6
30 -> 31
65 -> 66
As to 'server' you might have meant Gaia, Bodor or Quill. Once you choose one, you cannot move your character to another. Maybe start on Quill like Mae suggested, but also remember to try them all out.
(Gaia and Bodor are not bad options at all either
, but if you choose Bodor feel free to contact me, My IGN is walmazi)