Your PayPal ID is not the same as your account number or merchant ID. Instead, your PayPal account is identified by the email address that you log in with. If someone needs to send you funds using your PayPal account, you can ask them to send the payment to the confirmed email address registered on your PayPal account. If you need to find your Secure Merchant ID, you can go to your Account Settings, click Business information under "Business profile," and find your ID next to "PayPal Merchant ID". However, if you are looking for your PayPal account ID, you wont find it as PayPal does not have any account numbers shown by the public. Instead, your email is your account identification method. If someone has asked you for the transaction ID, you can find it by going to "Activity" and clicking on the transaction to see the details.

In summary, your PayPal ID is your email address, and you can find your Secure Merchant ID in your Account Settings under "Business information." PayPal does not have any account numbers shown by the public, and your email is your account identification method.