Most of this advice should go into the other thread started by the guy who hasn't sat on a bicycle for 10 years and is planning to ride across the US.

The guy in this thread is doing a 4-5 day "shake-down tour" of only 300 miles in familiar territory on a bicycle he has used for commuting for the past 3 months. He's fit. He has previous camping experience. It sounds like he knows how to fix bicycles. If something goes bad enough that he can't keep riding he can ring home for someone to pick him up and take him home.