I've been with PayPal for 13 yrs. Had a couple of small probs with chargebacks, but overall I've loved PayPal. I have a MC Debit card for my account so I can use it just like a charge card anywhere I shop.
Rena, don't you live in the US? If so, you can't use PayPal for anything to do with the casinos; that was shut down way back when.
As to an account number, I don't believe you have one with PP. Once you click "use PP" anywhere, it takes you to the PP site where you log in, then authorize the transfer.
You can deposit money to & from your PP account using your bank account. Also, if you get the debit card, you can use that at ATM's or stores.