Let me help you improve your translation. You did well overall, but there are a few details we can refine:
Your translation: "we discovered" Better: "I discovered" (the Spanish "descubrí" is in first person singular)
Your translation: "local fisheries had fresh fish market" Better: "local fishermen brought fresh fish to the market" ("pescadores locales traían" refers to fishermen bringing)
Your translation: "I was hosted in a place" Better: "I stayed in a small house" ("casita" specifically means "small house")
Your translation: "sounds" Better: "waves" ("olas" specifically means "waves")
Your translation: "habitants" Better: "inhabitants" (correct English term)
Your translation: "costumes" Better: "customs" ("costumbres" means traditions/customs, not clothing)
Here's the complete corrected translation:
"During my summer vacation, I discovered a small coastal town that left me amazed. The streets were adorned with flowers of all colors, and the local fishermen brought fresh fish to the market every morning. I stayed in a small house with a view of the sea, where I could hear the waves while having my morning coffee. The inhabitants of the town were incredibly friendly and taught me some of their traditional customs."