Everyone is a newbie at some point in time, so don't apologize for it.
As rsxn noted, moonlighting during residency is up to your program. Mine did not allow it under any circumstances - it didn't matter whether you were on vacation or under 80 hrs even with the moonlighting. Of course, they had been on probation for hours violations more than once so were a little touchy about the subject, Your hospital may have different rules and allow it during vacations, only in-house, or have no policy against it.
Attendings don't regularly moonlight unless they're having some financial difficulties or work in a specialty where they don't have restrictive covenants and have lots of time off (ie, EM). Otherwise, most people stick to the job they have either because they're already working enough hours or because their contract (if a hospital employee or in a group practice) prevents them from seeking work elsewhere.