You can read the articles about Connecting Data to learn how to use datasets. The wix-dataset API docs contains all of the details and features of a dataset.
As a quick example, depending on what you are trying to do, your code might look something like this:
$w.onReady( () => {
$w("#myDataset").onReady( () => {
let itemObj = $w("#myDataset").getCurrentItem();
if(itemObj.template === "1") {
$w("#box1").show();
} else {
$w("#box2").hide();
}
} );
Good luck and have fun,
Yisrael