The dominant advice I have is this:
This one is designed to cut through the ideas the internet told you are optimal builds, because things like 'oh, my DM doesn't enforce ______' or 'I'll always be able to buy more _____' go out the window.
You are going to want strength because you are going to want to be able to carry all the equipment into the jungle and all the loot back out of the jungle.
You are going to want Dex because medium+ armor is a problem. You are going to want ranged weapons because fighting dinosaurs and undead (with hp drain you won't get back until the end) from a distance/up in trees sounds like a really good way to save hps.
You are going to run out of arrows. You are going to need skills and utility and trapfinding.
What Should You Bring to Your First D&D Adventurers League Session
But also be good at fighting.
This is definitely the adventure that makes you feel constrained to only be one character.
As for optimal choices, I think moon druid, rogue, barbarian, and whatever you feel is best for undead (possibly just good distance blasting) for classes.
For races, dwarves (for poison resist), lizardfolk (for self-reequipping, Str/Dex utility, and nature skills), and Vuman would be good. Feats like Dungeon Delver, Inspiring Leader are good, but given that everyone will need as much of every attribute as possible, focusing on ASIs will not be a bad idea either.