Servers are all the same. Even if someone would recommend you one based on how many low level players they see, they (in 99,9% of the cases) wouldnt have any understanding about how the situation is on other servers for comparison.
Best advise is to pick a Server Name you like, because you'll be seeing it a lot.
You can always check how many transactions are done, giving you a slight estimation of how crowded the servers actually are. After that, you can either pick a server with lots of people, which will be great for starting out, but an absolute hell for endgame. A quiet server with less people, which is great for endgame, but makes starting out a little slower. Or anything in the middle.
Or... you know... you can pick a name you like and ignore all that... http://www.ffxiah.com/database