If you have forgotten your password, you can click on "Forgot your password?" on the login screen. You will need to enter your email address and click "Recover" to receive an email with a link (note: it may take some time to arrive, and remember to check your junk/spam folder).
The link is valid for 48 hours and can only be used once. By clicking on it, you can set a new password and use it to access your account. After 48 hours, the link expires, and you will need to click on "Forgot your password?" again to receive a new one.
The same procedure can be used to change your password.