Is there any way to see if Apple has paid me the proceeds from Apple Store Sales?
How to check if Apple has paid you?
Go to the 'Payments and Financial Reports' section for your account on App Store Connect (assuming that you are using App Store Connect to distribute your app). Find the relevant month(s) when your app was purchased. If your account has been paid there will be a 'Paid' mark next to a 'Transaction ID' for that month.
Also, check your bank account that you have setup (in 'Agreements, Tax and Banking') to receive your payments.