The Project feature in QuickBooks Online helps you track project income, expenses, and profitability. However, you can only set up multiple projects to one customer, not a single project for multiple customers.
Let me guide you through creating a project:
Turn on Projects
Click the Gear ⚙ icon at the right top.
Select Account and Settings under Your Account.
Go to the Advanced tab.
Find the Projects section, then select it to expand.
Select the Organize all job-related activity in one place box.
Click Save, then Done.
The Project will now appear on the left navigation bar.
Create your first project
Select the Projects menu.
Click New project.
Enter the project name, then select a customer from the drop-down list.
Add any notes or details about the project.
Check this out for a quick video tutorial about the process above: Set up and use the Projects feature. This article will also help you add income and expenses to your project.
Let me know if there's anything else you need and I'll get back to you.