Step1: Get a Bitcoin Wallet: you need a Bitcoin wallet to receive, store and send Bitcoins.
The easiest way is to set up a free account with Coinbase. With Coinbase account, you get bitcoin wallet to receive, store and spend bitcoins. You could buy and sell bitcoins through its exchange market.
Once you have a bitcoin wallet, you have bitcoin address to receive bitcoins. A bitcoin address is like e-mail addresses, you can send bitcoins to a person by sending bitcoins to one of their addresses. Bitcoin address looks like “1NV9qabf2CbCYjd5UiATasEaQLyDzt4bRG“.
Your bitcoin wallet automatically changes default address after each transaction to avoid being tracked. But the previous address is still valid. You could write down one address and use it to receive bitcoin payments.