Sure! Here's the translation of your text into English suitable for 5th grade:
Last summer, I went to the sea with my family. It was an amazing trip. The beach was very big and sandy. The water was blue and clear. I collected shells and built sandcastles. We swam in the sea, played volleyball with friends, and took many photos. It was very fun and exciting. I was happy and tired at the same time. I really liked this trip.