validation set to tune data

Hi, I need to divide my dataset into train, validation, and test and need to tune the models that I have based on the validation set. I know how to do it when we have trained and tested data, but I don't know how to tune my models based on the validation set and then find the mse or misclassification rate based on the test data. Can somebody please help me?

tidymodels treats validation sets as a single resample. Take a look at validation_split().