Your password should be randomly generated, longer than 12 characters and preferably generated and stored by a password manager. It must not not be shared between multiple services. No matter how complex your password is, if you use the same password on different platforms, you risk having your password compromised on a poorly protected site and reused on all your accounts.
A password manager is a tool that creates and stores passwords for you, so you can use different passwords on different sites and services without having to memorise them. They generate strong and complex passwords that humans are unlikely to guess.
For more about password managers, see the Electronic Frontier Foundation’s (EFF) resources on password security.