I don't know much about parking near the ground, but living in the borough I wouldn't do it. My advice is to park at Reedham station (just over 2 quid for 24 hours ringgo accepted). It is just off the A23 by Purley fire station. Or if there is a space round the corner on Old Lodge Lane past the railway bridges on the left - free. I park there if I am too lazy to walk.
Train to Norwood Junction at 15 and 45 past each hour, takes about 20 minutes. Use contactless on the oyster machines to pay. There are possibly options closer the ground or with more trains but that's what I would do.
Wish I could have got a ticket - it's my closest away game.