Air carrier Captain reported receiving a low altitude alert from ATC on a visual approach to CPR

Narrative

During approach to CPR; the FO was PF and the CA was PM. ATC offered a vector for a visual approach to runway 3. ATC gave a vector for a right downwind which took the flight closer to terrain to the south and east of the airport. The crew called the airport in sight and ATC cleared them for the visual approach. The FO then began descending in the downwind. About 7500 ft MSL; ATC communicated a low altitude alert; and stated the MVA was above the current altitude. The CA communicated back that they were leveling. The conditions were VMC and the crew could see all terrain around. The FO stayed at 7;500 MSL until turning base and no GPWS warning or any other issues came up for the rest of the approach.The cause was being unfamiliar with the area of the airport; and descending a bit sooner than was necessary. The PM could have also offered more communication and both crews could have had a better shared mental model. The crew could have also opted to get vectors for the RNAV GPS approach to runway 3 since they were unfamiliar with approaching from that side.Main suggestion would just be for crew to have a better shared mental model; better communication; and using ATC.