For secure passwords, aim for a minimum of 12 characters. Passwords of 8 characters are outdated and unsafe; some hacking tools can breach them in less than 6 hours. Also, using the same long password for multiple accounts is counterproductive; each password should be unique.
However, creating long passwords for all of your accounts can get overwhelming. To make this process easier, you can use a premium password manager like 1Password. With this tool you can create unhackable passwords, store them securely in an encrypted vault, and have the password manager auto-fill logins for you.