JSFiddle - React, Tailwind, and code Playground

HTML

<button onclick="startClick(1)">Click here</button>
<p>Money: <span id="money"></span>

JavaScript

var money = 0;
var xp = 0;
var level = 0;

function startClick(number){
    money = parseInt(money) + 50; //Want it to be random number to get
    xp = xp + 100;//Same here
    //This will update money,xp to your html
    document.getElementById("money").innerHTML = money; 
    document.getElementById("xp").innerHTML = xp;
}