Generally speaking, RO is not a very new player friendly game, however iRO RE:Start is probably the best server to play because it is only a couple of months old and is progressing through old content patches with updated mechanics. However it might be kind of tricky because the old content does not always reflect correctly in guides you might find online. The best resource will be iRO Wiki for most things if you decide to play any server, but this is specifically the restart link:
http://restart.irowiki.org/ Let me know if you have any questions.