Sorry for the confusion. At the moment, there is not much you can do other than buy and sell monsters, take them into battle, level them up and view them, and create rooms (which don't have functionality yet, but in the future you will be able to assign workers and have events). I appreciate your comment and I will work to add a tutorial, or elements that allow a better understanding of the game in future updates.
JAJAJAJAJ, don't worry. The battles are still not fully implemented and may have some bugs. For now, the attack, recover, and defend moves are the ones that work, and you should be able to select those. The grab move hasn't been implemented yet.
It's necessary to have a monster selected to perform an attack. However, recovery and defense apply to the character that attacked. Recovering allows you to recover the stamina points lost when attacking, and defending reduces the damage of the next hit received. At the moment there is no feedback (animation or visual element) to let you know what has happened. This is something I will work on in future updates to improve the combat feeling.