To level up you need to acquire a certain amount of EXP (Experience points) after you get the needed amount pm a admin about it and they will check to see if you have indeed gotten the EXP needed to level up.
Level 1 -100 exp
Level 2-200 exp
Level 3-300 exp
Level 4-400 exp
Level 5-500exp
Level 6-600 exp
Level 7-700 exp
Level 8-800 exp
Level 9-900 exp
Level 10-1000 exp
Level 11-1200 exp
Level 12-1400 exp
Level 13-1600 exp
Level 14-1800 exp
Level 15-2000 exp
Level 16-2400 exp
Level 17-2800 exp
Level 18-3200 exp
Level 19-3600 exp
Level 20-4000 exp
Note: You can gain EXP by hunting fiends, completing quests and many other things.