Congratulations on the sale! If the order was paid through Paypal, but you're not seeing the funds appear in the Paypal account you have connected in Settings/Payment Provider, then you'll want to reach out to Paypal support. When you reach out to them, you'll want to provide them with the information you find in the payment line of the order. To find this, you'll want to log in, click "orders" then click on the order in question. From there, scroll down to the "Order Timeline" and look for the payment line. Clicking the payment line will expand the information provided to us by Paypal. Here you'll find the information Paypal will need to locate the funds and to help transfer them to your Paypal account.
Let me know if you have any questions!