JSFiddle - React, Tailwind, and code Playground

HTML

<form id="myform">
    <input type="text" disabled="disabled" name="a" value="">
    <input type="text" readonly="readonly" name="a" value="">
    <input type="text" />
</form>

JavaScript

$("#myform :input:not([readonly='readonly']):not([disabled='disabled'])").first().focus();