If your friend is wanting to direct connect to you then your ip should be listed above the search box if you choose direct connect search type. If it's not, it means you're firewalled & any attempt to direct connect to you would fail.

Otherwise see http://www.whatismyip.com/ to find your ip address. There's other ways also.

For firewall issues, make sure your firewall software is configured to allow LW full access & make sure your modem/router UPnP is enabled. If it doesn't support this then manual port forwarding might be required. Instructions here Connection problems? Check here first! (click on link)

More on direct connect here How to use Magnet Links & Direct Connect. Also, another method is using magnet links. Check out the link. Once one person downlds or uploads a magnet link, you both can browse each other.