What is the most efficient way for the Salesforce Admin to fulfill these requirements?

What is the most efficient way for the Salesforce Admin to fulfill these requirements?

Universal Containers use Community to grant business customers secure access to accounts, orders, and invoices. Allcustomers are on a Customer Community License. Universal Containers plans to launch a project management module with the following requirements:• Leverage Chatter for collaboration.• Private project collaboration between the customer and Universal Containers.• Leverage documents, tasks, and events in the project space.• Customers can only see and access their projects.