Marriage Certificate for George Cupitt and Mary Wicks

I have been researching info on my family name - CUPITT . I would like to obtain the Marriage Certificate for George CUPITT ( born 9th March,1777 at Newmarket Farm, Derbyshire, England ) and Mary Wicks (b. 1777 , Londoneery Road, England )They came out to Australia aboard the 'Ganges' in 1797. Also any info concerning Mary and her family in England.