There are a lot of combinations of area words that you can put in. Before you go anywhere, the Chaos Gate tells you what kind of place it is - a field, a dungeon, all that - and what level the monsters are compared to your current level. You want to shoot for somewhere the monsters are higher-level than you, but not so high you can't beat them.

This one's a level 3 field, so it's about right for the both of us - I haven't been around long enough to do tons of level-grinding.