How can I do the following in the language R given datasets DATA_TEST.csv and DATA_TRAINING.csv:

1. Split the data set into a training set and a test set.
2. Fit a linear model using least squares on the training set and report the test error obtained.
3. Fit a ridge regression model on the training set, with chosen by cross-validation.
4. Report the test error obtained. You may choose the number of folds you wish or use LOO Cross-Validation.
5. Fit a LASSO model on the training set, with chosen by cross-validation. Report the test error obtained. EDIT: modified the premise + added a screenshot of part of my test and training dataset