Oil should be listed as VW "spec". Look on the rear label and it will show the 'spec' ratings. Castrol Edge and Mobil one. Both of these should meet the specs.
Go with about 4 and 1/2 quarts with the new oil filter (should be closer to 5). (Stay away from Fram..)
Normally auto parts stores will have specials for full synth and a quality filter.
Get the codes pulled asap and do NOT drive the car if the oil light in on steady. There's a chance either the oil level is just low in the crank case, or you have a clogged screen and/or busted oil pump. The dipstick tube is a common fail part, and isn't all that expensive to replace. I would urge you do so asap. Save the guess work.