Soy de Puerto Rico. (I'm from Puerto Rico)

or

Soy puertorriqueño. (I'm a Puerto Rican)

Puerto Rico, officially the Commonwealth of Puerto Rico (Spanish: "Estado Libre Asociado de Puerto Rico" - literally Associated Free State of Puerto Rico), is a self-governing unincorporated territory of the United States located in the northeastern Caribbean Sea, east of the Dominican Republic and west of the Virgin Islands. Puerto Ricans are US Citizens since 1917.

Puerto Rico is a territory within the US. That means they do not have as many liberties in politics as do the states. Puerto Rico is also a Caribbean island with Spanish history, meaning its culture is very different. However, Puerto Rico has been Americanized over the years.

San Juan is the capital of puerto rico

No, Puerto Rico is an island.
Actually Puerto Rico is NOT a continent ; it is an island .