Sorry to hear about your father. If you're buying this car with the money he left you maybe you'll think of him very time you drive it so not necessarily a bad thing to do!
Prices vary incredibly! Spend a few more pound and get a high spec one....
Go for leather, highline clocks, 18" monzas, xenon lights, dual zone climate control, sunroof, multi function steering wheel, upgraded head unit....
Those are some of the main ones. I personally prefer the manual gearbox but the DSG if serviced on time is a good call!
Expect to spend around 8k for a great one or 6k for mediocre spec.
Get something good or always regret when you see another GTI pass you with their auto levelling xenon headlights!!