This project is a big time investement. It’s impossible to do if you’re alone or 2, so you need to manage your work load. Spread the work evenly between your team members. This allows each member to focus on their task so the entire project can move forward. Don’t neglect certain aspects like the 3D design or coding as they are very long, hard and tedious tasks.  

We use Notion for the organization in our team. It is very usefull to basically make a to do list with a lot of functionalities like deadlines, respopnsibles, priorities.

Here is our Notion, (you can quickly see every task that we made for the project)