The Novice Training Grounds is the area where all new characters are sent to as Novices. It has many tutorials with free EXP and items for the new players.
Most novices stay in the Training Grounds to reach Novice job level 10, when they can finally change to new classes.
The Training Grounds seems to be in an unknown area in the world of Ragnarok, it may be found on a separate island far from the others. There are no available Kafra in the area too. There are also areas normally inaccessible but only with the use of Fly Wings. Once you get out of the Training Grounds, there is no possible way on how to get back to the area.
The map of the Training Grounds is shown below. Red dots mark the entrance to other areas.