Just be wary when doing freelance writing, especially when it comes to the pay rates. There are some dodgy people around who will offer you an obscenely low amounts of money, so I suggest that you also research what the going rates are.
Finding work also depends on the medium you're looking at. Digital publications are often easier to get work with, than magazines and newspapers.
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Here are two websites that may help you find clients, but they do require you to pay for a yearly subscription. There's no doubt more sites like those are out there, and there's actually forums dedicated to freelance writers you may wish to search for.
All the best!
Lee