let kol = document.querySelector('.kol');
let c = document.querySelector('.cili');
let cs = 0;
c.onсlick = function (){
cs++;
kol.textContent = cs;
};<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" type="text/css" href="css/style.css">
<title>Сайт с JS</title>
</head>
<body>
<p class="kol">0</p>
<button class="cili">Клик</button>
<script src="script/script1.js"></script>
</body>
</html>c.addEventListener('click', function (){
cs++;
kol.textContent = cs;
});