Getting out of check is lesson 2 of 4 in Check, checkmate and stalemate, a basics course suited to players rated around 300 (complete beginners). There are three ways out of check: move the king, capture the attacker, or block the attack. It has 3 interactive exercises: 3 find-the-move puzzles. You play every move on a board and get feedback straight away. The lesson is free.
What you practise
Your king is in check from the rook. Move the king out of the line of fire.
Check from the black rook, and your king has nowhere to go. Capture the attacker!
Check along the 1st rank. The king cannot move. Block the check by putting a piece in between.