As the accommodation is arranged by the University if you chose to rent an apartment you might be isolated from the rest of the Erasmus group. Why? Because most of the social life is happening here in student housing. It is because Huddinge is located 20 minutes by train away from Stockholm center. And at night you have to take the night bus - this takes more than 1 h.
As a result, nobody feels like going and all the parities and other activities are organized here in common kitchen. So, if you are new and want to meet people simply check out the kitchens. There will be somebody there cooking common dinner or organizing a beerpong party.
From my experience cooking together is a really good way to make new friends and pend nice evening and some of the kitchens are big enough to throw a regular party. And as lot of us are staying for holidays it is also a good idea to organize international celebration of f.e. Easter holidays. This is how I learned about many traditions from all parts of the world.
Another plus of student housing is the nice neighborhood and proximity of the forest, what make the place ideal for organizing a picnic, grill or even hiking tour.
The opportunities are countless - all you have to do is to get out of your room.