i want to know how to service the car i.e air filter,oil filter,fuel filter etc

minor service = engine oil and filter change , check lights and visually check for any other component failure
Full service = engine oil and filter change , check / change spark plugs , air filter , fuel filter , pollen filter . Remove wheels , check brake pads , shoes , discs and cylinders . check all suspension components and all brake and fuel lines , check lights , grease door , bonnet and boot/trunk lid hinges and latches , check seat belt operation , check all fluids ( brake fluid , power steering fluid , gear oil etc ) check wiper blades , check universal joins for play , check drive shafts for wear and c.v. gaiters for wear and attachment
Major service = all of the above plus head light aim , oil flush , change gear oil , change brake fluid , replace timing belt and kit , flush water system and replace antifreeze

go to an audi authorised service centre