Your Discord password must contain at least 8 characters in order to be valid. Less than 8 character passwords won't be accepted.
Use a strong password that is unique to this website alone. Generally speaking, longer passwords are more secure than those that contain more symbols, digits, or letter cases. For each website you connect into, using a password manager is a terrific method to create, secure, and remember strong passwords.
There may be extra password restrictions that apply to your location.