Hello there, carylbaron1.
Let's first make sure the customer is added on your customer list. I'll walk you through how:
For your reference on how to set up a new customer, check out this article: Manage your customer list.
Once done, you can now create a budget. I'd be happy to walk you through the steps below:
I've got an article made handy for you to learn more about managing budgets in QBO: Create, edit, and manage budgets.
Should you need help with anything QuickBooks, just let me know. I'm here to help. Have a good one.