We'd parked in the National Trust Car Park and walked across the fields to the beach.
Other people park at Horsey Gap. I'm not sure of the difference in distance but the walk behind the dunes from the Horsey Gap park is less muddy.
On the way back you might refresh yourself at Nelson's Head and enjoy the church. If you do see if you can find a prayer book and turn to Psalm 8 :
3 When I consider thy heavens, even the work of thy fingers; * the moon and the stars which thou hast ordained;
4 What is man, that thou art mindful of him? * and the son of man, that thou visitest him?
5 Thou madest him lower than the angels, * to crown him with glory and worship.
6 Thou makest him to have dominion of the works of thy hands; * and thou hast put all things in subjection under his feet:
7 All sheep and oxen; * yea, and the beasts of the field;
8 The fowls of the air, and the fishes of the sea; * and whatsoever walketh through the paths of the seas.
9 O LORD our Governor, * how excellent is thy Name in all the world!