I am assuming that you set up just a normal account at Paypal using the same email that you use for registration with companies and have provided that email to your companies. (If you use a Paypal account that uses a different address you need to also authorize your email address you use for shops.)
How do you plan on getting your money from Paypal? Your options are with a Paypal debit card (use like cash and places that accept a debit card or pay ATM fees if you want cash in hand), have them mail you a check (I believe there is a fee associated with this), or have them transfer the money to your bank account. If you are having them transfer money to your bank account you will need to set up the link between Paypal and your bank. This requires the 9 digit routing number and your account number and can take seconds or a few days to verify a few penny ACH deposit to your bank account. If this is set up . . .
When payment is received at Paypal an email will be sent to your address telling you that ABC has sent you $xx.xx. Log into your Paypal account to verify it is there and mark your records that payment was received so you aren't still looking for it. If you are using a debit card you are ready to spend it, if you are having them send you a check I believe you need to put in a request for it, if you are transferring the money to your bank you need to go to the 'Withdraw' tab and go through a couple of screens to get the money on its way. The transfer to your bank they say takes 3-4 business days though I usually find it is faster than that.
I use the transfer to bank and when I have successfully entered the withdrawal I will get a confirming email from Paypal usually in under an hour. When I receive the money at my bank I delete that confirming email.