Hi,
Have you tried Google? You can find a lot of hits for 'Joseph Andrews' novel summary. For example,
In Joseph Andrews (1742), Fielding's first novel, footboy Joseph loses his place when he rejects Lady Booby's advances, commencing a comic odyssey of robbery, poverty, and sexual viciousness.
Since you are studying English literature, another alternative would be to read the novel itself.
Best wishes, Clive