Your username is case sensitive and can not be changed.
Your password is case sensitive.
Using free email providers like Outlook/Hotmail, Gmail or Yandex is discouraged.
Use a password manager. Something like Keepass, Lastpass or 1Password. This helps you to not lose your login information and makes it much easier to use and remember strong, complex passwords. It's extremely useful and a good security practice!
Some other considerations:
Your IP address is logged.
Account sharing is prohibited.
The use of disposable email addresses is prohibited.
Creating multiple accounts is prohibited.
Once your account has been created, it can not be deleted.
By logging in and enabling furry or NSFW content preferences on your account, you agree that you are:
of legal age in your country of residence
it is legal for you to access NSFW and/or Furry content