If a pinch runner comes into a game and ends up coming around to score who gets credit for the total bases and run scored - the pinch runner or the player who reached base in the first place?

Total bases is not relevant with pinch runners. Total bases is only relevant with batters and is a statistical category used to measure a Baseball player's effectiveness at the plate. So the pinch runner would be credited with 0 total bases. However, the run scored would be credited to the pinch runner.