I cant get a demo to work

I just want to make a small demo to run locally, but I cannot get it to work for the life of me. IDK what I am doing wrong. I have just copy and pasted the Links and script and sample code but the browser will not render it properly.

The mistake I usually see is failing to include a <script> element to load jQuery before the <script> element that loads Select2. So make sure you’ve included jQuery.

If you have, then it would be useful if you could put your sample code on a site like codepen.io or jsfiddle.net, so I can look at it.