what would be the best detailed resources for me to research the
following--have any civilizations NOT had slavery, in some form, as
part of their history?

Depends on how you define "slavery."  There are many different forms
of forced labor and denial of freedom.  NOte: I'm not an official
researcher and this isn't really an answer but more of a comment.  My
guess is that most countries if not all countries have had some form
of slavery at some point in their history, and many still do to this
day disguised in non-traditionally recognized forms-i.e. the prison
industrial complex's complex relationship with corporations can be
traced back to the South's prison system relationship with former
slave owners immediately following the official ban of traditional
slavery.

Human trafficking of immigrants into the U.S. from Latin America as
cheap labor and trafficking of girls as sex workers from every part of
the world is definitely a form of slavery that is unnoticed and
tolerated.