Combat:
Head out of town - pretty much any direction will do - and start targeting the creatures you see to see which ones are safe to attack and which ones you should keep Aion Gold away from. There are two things you will notice when targeting.
First is the description in the action window. It will tell you how that creature feels about you. Anything short of aggressive means you can go up to it without worrying that it will attack you. If a creature is aggressive to you, be ready to get attacked if it sees you, and if it has friends nearby, they are going to attack too.
Thus, before getting close to anything, target them from a distance and see how they are going to react to your presence.
The second thing you will get from your target is a level description of the creature. After you target the creature, check the box in the lower right hand corner that shows your stats. It now shows the name and hit points of the targeted creature right below your stats. The most important part of this is the color key for the creature's name.
Thus, a red with two plusses is two levels higher than you or a blue with one plus is one level below you.