Q: forgotten password on my icloud email

It's the same as the password for your iCloud ID.  If you've forgotten it, you'll have to reset it using one of the methods discussed here: http://support.apple.com/kb/HT5787.

If you know the answers to your security question, or if you use two-step verification and have your recovery key, you can use one of the other methods shown in the linke article posted above.

If you don't, and you can't get email authentication to work, you'll have to contact iTunes store support and ask for assistance.  You can reach them here: https://ssl.apple.com/emea/support/itunes/contact.html.