There are quite a few multi storey car parks around the town.
I hardly ever park in the town, because I live within walking distance, but ...
I think one of the cheapest places to park is in the car park at the bottom of Trafalgar Street, just down from Brighton Station. From there, it's an easy walk to anywhere in the town.
had alovely day thanks! there are lovely shops there, found the car park and was perfect for getting to the shops! and even better my friend paid parking in the end