where can i access all of the salesforce exam guides?

How do you update a require field using the process builder? I need to populate *required Fields from lookup (account shipping fields)

Messed whith field encyption, after disabling it and continuing to trailhead to complete module its throwing in error saying it is still encrypted although i can clearly see it in my dev org. i cant find a solution is their i fix for this or do i really have to contact salesforce and hope they fix it? 

How do you update a require field using the process builder? I need to populate *required Fields from lookup (account shipping fields)