Facebook usernames and user IDs are part of your public profile, which can help your friends find you on Facebook. You should choose your real name, indicating that your facebook account belongs to a real person. So how to change Facebook name?
Change facebook name
Click Facebook “settings”.
Click on “edit” next to your name
Type in the new information and click “Review Change”
b: If you change your name on Facebook, you can’t change it again for 60 days.
Your name can’t include: Symbols, numbers, unusual capitalization, repeating characters or punctuation. Characters from multiple languages. Titles of any kind (example: professional, religious). Words or phrases in place of a name. Offensive or suggestive words of any kind