Being a successful freelance translator is all about contacts. You can have all the diplomas in the world but without being well known you won't get anywhere.
Most translators work through agencies and are given work through them. Generally speaking, a translator will accrue experience and thus contacts over the years.
If you register with an agency you will generally need to have "specialisms", ie subjects you have an in depth knowledge of. Some texts can be very technical (ie legal, IT, science etc) and if you haven't really got these extra things you may have to learn.
It's a very competetive business for European languages. As lots of people have them, you can't expect to be paid as much as you would for the Scandinavian and Asian languages for example.
Literary translation is phenomonally difficult to get into. You would not be able to survive from this, certanly not at the start, and would almost definitely need to focus on the more mundane subjects like washing machine manuals etc.
Generally speaking you will need to be prepared to take on work whenever its offered, overnight, weekends etc. If you don't, you will lose credibility very quickly.
I used to be a translator and have also worked as a project manager at an agency which is how I know all this.
I hope I haven't put you off: it's just people often have quite romantic illusions of translating Proust in their front garden. In reality it's a hard world to break into, subject matters can be very dry and the pay is not very good at all. In fact, at my agency, the hourly rate of pay had actually fallen over the past few years as the market was so competetive.
Hope that helps!