You should always have two step verification enabled on your account. Although it might seem annoying, it allows you to add a backup email or number which you can use to confirm its you when you login to a new device and crucially reset your password without having to contact support (we're guessing you've forgotten your password as you're on this page).
If you have 2 step verifcation enabled on the login screen you can simply select forgot password
Once you have clicked on forgot password follow the screens through and you'll be able to reset your password after verifying your identity.
So you've not got 2 step verification enabled? You'll need to contact an administrator. You can do this by contacting support who will reset your password and allow you to login again. You'll need to change your password once you have logged in with the temporary password given by the administrator. Use the button to contact support.