If you have a big project with lots of tasks, this project management tool is a big help. Trello is like using sticky notes on a wall with all the little jobs that need doing. This idea is called a KANBAN board.
If you'd like to organize your team using Trello first login and create a new board. Then send the invite link to your teammates onto the board using a link.
Create a folder in your Google Drive, right click on it, select the share options and share it with your teammates. Now you have a folder in which you can all exchange files.
When you share a folder with someone, they need to accept it in the "Shared with me" section on drive.google.com