You are allowed to create multiple characters. However, you must first fulfill certain conditions:
-For the second character, your first character must reach level 5.
-For the third character, you must have a total of 250 experience on both of your accounts. Also, they must both have obtained at least 50 experience since the creation of your second character.
-You cannot have 4 characters at once.
When you create a second or third character, you must create a new account. After this, you will need to get it validated like with your first character.