I didn't really have one. I was older, knew the city well and had my groups of mates already. The result was that I didn't fret about it.
I did, however, meet two people on my first day that are still close friends now. Not enough to class as a 'group', perhaps, but still. They, like me, were older and had been around the block once or twice
When I was in Oxford over the past year, it was similar. The majority of my course mates were almost 15 years my junior and I didn't connect with any of them. So I made mates in the local biker boozer, with lads with whom I shared common interests