Daniella's Beach is listed as a park in Mana, Porirua, with a Google rating of 4.6.
A good coastal park gives people space to walk, look out over the water and unwind, with clear paths and somewhere to stop. Where there is a beach, the main things to know are that tides, swells and currents change quickly, that water is cold even on warm days, and that there may be no lifeguards, so regulars check conditions first, keep children within arm's reach and never swim alone. The coast around Porirua can be windy, so a windproof layer and sun protection are both worth packing, and early mornings and late afternoons are the quietest. Wear shoes with grip on rocks, carry water, respect any signs about swimming or dogs, and take your rubbish home.
For people in Mana and around Porirua, Daniella's Beach is a well-rated local spot to enjoy the coast.