The first move in finding yourself a social life is often seeing an advert in your local paper and picking up the phone. The most difficult step can often be just picking up the phone.
Clubs and societies can be a good way of meeting people but often require you to be good at a specific hobby or interest if you are to be valued by the group. However, there are also singles clubs and places that exist simply for the purpose of meeting people.
Voluntary work is advertised in the papers and probably also in your local library.
Also, it could be a very good move to enrol in an evening class. Counselling courses and psychology classes may give you a lot of extra insight into social interaction. Even if you don't actually pass the exam, you could easily find yourself drawing more benefit and reward from the course than any other student.