Welcome to the QuickBooks Community. I can help figure out why you can't create invoices.
We'll need to check the access given to you by the Company or Master admin. You'll need to have permissions to access the areas of Customers & Sales to be able to create invoices. You can let them review your access rights to the company file to ensure you can access invoices.
Here are the steps on how to change a user's access rights:
Click the Gear icon.
Select Manage Users.
Choose a user.
I also have an article here that'll explain to you all types of permissions. You might want to check this article: