Just had a quick look on justpark.com and there are spaces from about £6 if you don't mind walking from Tunnel Avenue (handy for getting away north after the game) Tunnel Avenue is a 15-20 minute walk to the ground but there are probably buses too.
Very limited parking around The Valley, footychick. Last season (Boxing Day) I parked up by Charlton Park and walked down Charlton Church Lane to the ground. Charlton is a very residential area with keenly monitored parking restrictions.
I first drank in the Princess of Wales 40 years ago. I had my first (and last) pint of Carling in there. It always was a nice pub, just a little bit out of the way it seemed
T'was going to be my pub of choice before I found out about the train service (or lack of)
As FatAddick says there is nothing in Lewisham. There never, ever was a decent pub there so don't bother now.