Jquery td to Javascript td

I have this in jquery all works:

    $(document).ready(function () {

        $("#checktable td:nth-child(1)").click(function (event)  //  This line I need converted
        {
            event.preventDefault();
            
            var $td = $(this).closest('tr').children('td');  //This line I need converted
            var tid = $td.eq(0).text();
            var tdate = $td.eq(1).text();
            var tdescribe = $td.eq(2).text();
            var wd = $td.eq(3).text();
            var dep = $td.eq(4).text();

            // more code
           

I need a similar thing in javascript, above only first td is clicked.

My javascript code so far:

    function addRowHandlers() {
        var table = document.getElementById("checktable2");
        var rows = table.getElementsByTagName('tr');
        var tid = '';
        var tdate = '';
        var tdescribe = '';
        var wd = '';
        var dep = '';
        var tisclr = '';

        for (var i = 1; i < rows.length; i++) {

            rows[i].i = i;
            rows[i].onclick = function () {
                tid = table.rows[this.i].cells[0].innerText;
                tdate = table.rows[this.i].cells[1].innerHTML;
                tdescribe = table.rows[this.i].cells[2].innerHTML;
                wd = table.rows[this.i].cells[3].innerHTML;
                dep = table.rows[this.i].cells[4].innerHTML;

               // etc more code

The javascript works but any td can be clicked, I am after only:

• First td clicked
• Then get parent row
• Then all child td's

I have been over dozens of stackoverflow post and other sites as well... Thanks

And how do I add the event.preventDefault(); to regular JS in such a case.