Since bastards in GameSpy cut the support for NWN2 many a year ago, online community has organised itself and managed to get things running again:
http://www.nwnlist.com/ - this is the list of available servers for NWN2 (and, by the way, for original NWN), complete with their IP numbers; on that page is also a NWN2 client extension (LINK:
http://nwvault.ign.com/fms/Download.php?id=169006), which you need for an in-game list of available servers - or, if you don't want to dabble in that, you can just see the IP number of a server you and your mate want to play on and type it as the "direct connect" option.
Once you and your friend are on the server, you can both look for other people, ask for help and, of course, form separate parties. Beware tho, a lot of RP servers take RP seriously.