You can find your wallet address by navigating to the Addresses page or by clicking the Tools menu from the menu on the left.
You'll see that you may have multiple addresses associated with your account - you can use any of these addresses for receiving bitcoin or ether, as long as it is the correct address type for the digital currency you wish to use.
Don't be alarmed if you see addresses that you don't remember creating - we automatically generate a new address for every transaction and whenever we move funds between your wallet and our cold storage system. For more information on this, check out: Why did my wallet address change?
Clicking the 'Details' button for an address will provide some additional information about that address and allow you to set a label so you can keep track of which addresses you've used for what. From this view, you can see a QR code which can be scanned or embedded in your website. You can also sign a message with the address.