Preston Park is a great family park with a range of amenities, some of which are more obvious than others. It's on the main road into Brighton (from London) and has parking on site. However, it varies which car parking areas are open or closed - probably to stop commuters parking there for the day. The park is about 2 miles from the sea front.
As well as lots of grass for running round, playing football and exercising dogs there are tennis courts, children's play parks, bowls greens, a rose garden and cafe (Rotunda) and basketball courts. It also has a cycle track tucked away out of site, which has a cricket green in the middle of it. In addition there is a scented garden and a number of paths leading hither and thither. Preston Manor backs on to the park - I believe that manor and park were donated to Brighton by the owners many years ago.
Preston Park is often used for events such as races, circus performances, music festivals and Pride carnival. Check it out!