Air carrier First Officer reported a terrain obstacle warning while descending on a charted visual approach in daylight VMC conditions. The crew identified the obstacle; corrected the flight path; and landed safely.

Narrative

While flying the River Visual Runway 19 into DCA on Day 0 we received a terrain caution followed by a terrain EGPWS warning indication. Conditions at time of the event were day VMC. The autopilot was off and I was hand flying the visual approach at time of the event. The approach was heavily briefed and we were configured and stable at 1000 AGL; but my initial descent on the approach was too steep resulting in finding ourselves lower than we should have been. After receiving the caution the obstacle was identified as a crane to our East associated with some taller buildings. The altitude and flight path was corrected immediately; but as I stated it was briefly followed by an EGPWS warning. We decided that since it was day VMC; the obstacle was identified; and our location was over the middle of the river with considerable distance from the obstacle we corrected the flight path and continued the approach. The warning immediately went away and thereafter had sight of PAPI's in which we corrected flight path to maintain a stable descent to Runway 19 with no other issue.Both the Captain and I were inexperienced with the River Visual Runway 19. Which we briefed about heavily prior to the flight and then again prior to executing the approach. It was my very first time flying the approach and they said that they had only done the approach a handful of times. This was certainly a threat identified in our brief and in our de-brief at the gate in DCA. In addition; ATC gave us a tight right hand turning vector to intercept the river at 3000 MSL in which we both struggled to initially identify the river based off of our inexperience with the approach. This was the catalyst that put us behind the aircraft while I am trying to fly the approach for the very first time in addition to being configured and stable based off of stable approach criteria. Ultimately; it was inexperience with the approach; task saturation; and poor situational awareness based off the suggested altitudes on the approach chart that led to this event. If crews are inexperienced with an approach as complicated as the River Visual Runway 19 before flying the approach as pilot flying my suggestion would be to at least see it once first in the real world as pilot monitoring while the other crew member (barring they have more experience) operates at pilot flying. Hindsight this is what I wish I would have suggested to the Captain prior to operating the flight into DCA.