@tanguatlay,
Last Sunday, my family and I went to the beach at the East Coast Parkway. As(1) we stepped onto the sand(2), a gentle breeze blew in(3) our faces.
My brother and I rushed to the public toilets to change into our swimming attire. My parents laughed to see us in such a hurry.
After my brother and I had changed, we ran to the sea. After we had swum for about half an hour(4), our mother called us for lunch, which consisted of peanut butter sandwiches.(5)
After we ate,(6) my brother and I took a nap. After this(7), our parents joined us for a swim, following which we showered at the public toilets, packed up and went home.(8)
(1) The breeze was blowing as you stepped on the sand. If it sprang up at the very moment you stepped onto the beach, then you would use 'when'.
(2) Avoid over frequent repetion of the word 'beach'
(3) A breeze blows in your face, I think, rather than 'onto' it.
(4) Originally it was your mother who swam for half an hour!
(5) Avoid repetitious short sentences with many occurences of the word 'lunch'.
(6) Avoid repeating the word 'lunch'.
(7) It is understood that you woke up from your nap.
(8) Join the short sentences together. Makes the style less staccato.