I'd say if you wanna choose one, choose one of the most popular.
Those would be
Lawolf
Aibatt
Mia
(Ordered - first = most in my opinion)
I'm on Lawolf and the % of high and low levels and beginners are good.
Many people just started there but there are alos enough old players to help you to get in the game.
But like all old Server the prices are quiet high...
If you decide to start on Lawolf, just dropp me a message
~ There is also a complete german Version with 2 or 3 Server Clusters available if you're german and prefering this.