Alright, what exactly can I do to make this work?

Let's say you have the world ready, but you don't know how to make a "working game". Don't worry! We can help. First of all, make sure to set everyone's spawn point in the starting ship. Then, add "tasks". In order for this to work, every task will have a barrel and a hopper. In order to complete the task, crewmates will need to deposit a certain amount of "crewmate items". This might be diamonds or something. (It does not matter what the item is). The players will have only one of these items at any given time, and it refills instantly. This means they have to stay at the task for the given amount of time. In order to make this command work, type this command in a command block:

"/replaceitem entity @a slot.inventory 0 diamond". Make sure imposters also have the item, or else people can say they're crew by holding the item.

Once a container has reached the needed amount of items, use a detection system to figure out when it got enough. I recommend using a scoreboard for this. Whenever the item is detected, execute this command to the "taskbar scoreboard". /scoreboard players add "Task" task 1. This is a very simple system, so you will need to add more than that. If you want to make a way to report bodies, then you need to use an XP system. When someone dies with XP, they will drop it. meaning you found a way to detect if someone died. YOu can then execute commands at the XP orbs. (Cool!). Now that you got a basic idea on how to make an Among Us game, download the world, and have fun!