Taking pieces is lesson 1 of 3 in Capturing pieces, a basics course suited to players rated around 200 (complete beginners). You capture by moving onto a square where an enemy piece stands. The captured piece leaves the board. It has 5 interactive exercises: 5 star-collecting exercises. You play every move on a board and get feedback straight away. The lesson is free.
What this lesson explains
The rook can capture the black pawn: it moves to d5 the normal way and the pawn is removed. Every piece captures the way it moves (only the pawn is different).