the land next to a sea, seashore
No. This is untrue.
literally: coast of the sun sunny coast
The Wild Coast.
If you mean the American east coast, that would be the Appalachians.
If you mean country then Gold Coast is located in Queensland, an AUSTRALIAN state.
The Wild Coast.
unknown
Coast guard
The French Riviera. Lit: The Azure Coast or Sky Blue Coast
Well coast means the edge. So when somebody says "The coast of California.", they mean the edge where land meets the sea.
There are several areas called the "sun coast". The Gulf coast of Florida, for one, and the east coast of Australia (near Brisbane) for another. You would need to be more specific.
Since a large number of countries border the pacific ocean, it depends on which "pacific coast" you mean. The pacific coast of the USA is its west coast.