After she got Tokyo, she was told that she would join the High School Volley Ball team, which was her mother's alma mater team. She had never played volley ball before, but with her fundamental skills, she quickly became the key player on the team.
The morale of the story is that no matter what we are doing, the fundamental skills are important. For volley ball, they are running and jumping. For chess, the fundamental skills are tactics, tactics and tactics.
Tactics is so important that the whole Steps Methods is 90% about tactics.
If you are a beginner, you have to start with tactics. At this level, you can't grasp the whole picture of a chess game. Learning opening is almost useless. It's like war vs battle. A chess game is a war, and tactics are battles. Beginners only understand battles, Talking about wars is futile. You should try to win most battles to win the war, i.e., the game.
That's why I encourage kids to practice tactics, as much as possible. After solving 5,000 tactics problems, you will see big improvement in your child's play.
Here are some books I recommend: