Hi rsrayala, welcome to MobileRead!
If you scroll down the forum you will find a subsection E-Book Formats with a subsection Kindle Formats and a subsection for the calibre software.
Browse these fora, especially some of the posts concerning pdf-conversation, for instance this one:
https://www.mobileread.com/forums/sho...d.php?t=239092
Don't have any illusions, you will have to do some manual changes to get a working table of content.