We just bought our first Passat!

Hi everyone

After lurking on this excellent forum for quite a while we finally bought our first Passat first Volkswagen actually.
It's a 05 TDi estate Highline 130 tip auto. Has to be auto as hubby has had 2 knee ops and it has to get me a 4 mile trip to work and back but also take 4 of us plus 2 big dogs away towing a caravan.
Hope we have made the right choice?
First question probably of many..........
After starting it after about 10 seconds it makes like a warning sound through the speakers. No lights come on the dash. It does it if you don't pull away but didn't do it when I pulled away immediately. The other times I was trying to find light switches and stuff.
Any ideas?
Thank you very much :confused::confused:
Lynn