You can use DC++ Off campus, but you should note it will never be as fast as it was on campus, somewhere between 30 and 100kB/s depending on how lucky you are with the person you are downloading from. Generally we suggest that unless you are after rarer things you are better off torrenting. There is a guide to setting up your connection for off campus at http://www.twofo.co.uk/wiki/index.php/Off_Campus but you ought to be able to just choose the Off Campus connection option in View -> Favourite hubs to be able to connect/chat/ask questions (if you got the twofo configured client anyway).
As for using campus....you would need to be in a room on resnet, library/wireless etc won't work at all I'm afraid. General advice there is to pull a fresher