When you lose your password, you will need to reset your own password. This is the most secure method so that we never know your password.
Go to your website and add /wp-admin to the end of the url. (for example, if your domain name is "ilovepuppies.com" then go to "ilovepuppies.com/wp-admin" and click the lost my password link. Enter your username or email address and you will get an email with a link to reset your password.