I'm living in Chigasaki, Japan, whereich is a very famous as a sea town. I'm living in Chigasaki, Japan, which is a very famous sea town.

Referencing something just previously mentioned (Chigasaki) => which is = Chigasaki is

I'm living in Chigasaki, Japan, whereich is very a famous as a sea town. I'm living in Chigasaki, Japan, which is very a famous sea town.

I'm livinge in Chigasaki, Japan, whereich is a very famous as a sea town. I live in Chigasaki, Japan, which is a very famous sea town.

So I often wear sandals at alloften, (every season) except for winter. So I wear sandals often, (every season) except for winter.

Leaving off "every season" would be cleaner without losing anything

So I often wear sandals at all seasonll-year-round except winter. So I often wear sandals all-year-round except winter.

So I often wear sandals atin all seasons except winter. So I often wear sandals in all seasons except winter.

Surfing is also famous in my town, but I've been (too) afraid of the sea since I watched " Jaws" when I was teenager. Surfing is also famous in my town, but I've been (too) afraid of the sea since I watched "Jaws" when I was teenager.

I would use "too" here because you are indirectly saying that you are "too afraid" to go surfing because of Jaws.

SurfingMy town is also famous in my townfor surfing, but I've been afraid of the sea since I watched " Jaws" when I was teenager. My town is also famous for surfing, but I've been afraid of the sea since I watched " Jaws" when I was teenager.