There are a few options which change the fee structure, access to funds, and may affect others' willingness to send you money.
First, you need to set up a paypal account (it sounds like you already have one). You need to provide some basic info to paypal here, name, address, etc.
Once you have a paypal account, you will be notified by email whenever someone sends you money...sometimes the emails are slow or get caught in spam filters, so you could always log in to your paypal account and check. The money sits in your paypal account as "paypal funds" until you spend them or become verified.
You can link your bank account to paypal to make yourself "verified". Here you are providing additional info to paypal including bank account details. The benefits of being verified are 2-fold:
1) it allows you to take the money out of paypal, rather than letting it sit there until you are ready to buy something using paypal.
2) Many individuals will refuse to send you money if you are not verified (since you could be using totally fictitious info and running a scam).
The second set of options arises when making a payment arrangement. There are basically 2 options:
1) Someone sends you money as a gift, if they pay with a credit card, the sender will pay a fee, there is no fee if they pay with funds in their paypal account or from their bank account. Some people will be willing to send money as a gift, some won't as this leaves the sender little recourse if the receiver wants to scam them...they could pursue legal action or charge back their credit card, but could not get a refund directly through paypal.
2) Someone send you money for goods or services. Then the receiver will pay a fee, and should send the product with delivery confirmation. Paypal will mitigate any disputes between the sender and receiver.
The fees get smaller under 2) above if you sell a lot and are verified.