xxxxxxxxxx
// select the element to hide using its ID
let elem = document.getElementById('elemID');
// set the display to "none", hiding the element...
elem.style.display = 'none';
/// --- you can also do it in 1 line without using a variable,
/// --- as per the example below:
document.getElementById('elemID').style.display = 'none';
/// --- Bonus: if you like using jQuery, then you can hide elements as like so:
$('#elemID').hide();