Hello @SaoriYamguchi
Thank you for posting on the Community!
There is a great response on the post "Test accuracy of predictive model on new data" that goes over how the performance scores (accuracy, F1, precision, recall) are determined.
I am including a few other posts from the Community that cover similar topics for you to check out!
Decision Tree - Precision and Recall values - Are they correct?
Tool Mastery - Decision Tree
Understanding the Outputs of the Decision Tree Tool
Decision Tree tool - Help Document
I hope these help to provide you the better understanding you are looking for!
TrevorS