Often better and more complete than w3schools is MDN
https://developer.mozilla.org/de/
Generally achieving tasks like finding user location is done via Java Script APIs.
You always use more than plain HTML to create a website.
You use HTML for structuring the web page content. CSS to style the web page and make it look like anything.
Java Script is used to make the site dynamic beyond the most basic CSS and HTML features.
However this is only what's run on the browser side of the website. The website also has a Server side where the Server receives a Http request and then makes a decision how to respond.
On the server side you have languages like PHP which is run on an Apache Server or Java or Python (Go, Perl, Ruby, server-side Java script... ) . On the server you might also have a database that communicates in SQL.
To make using these languages easier people often use libraries for these languages.
jquery is probably used on the majority of web sites. It has gone beyond a simple library and has essentially become part of Javascript itself. (e. g. If you ask a question regarding Javascript on Stack Overflow you explicitly have to say that you don't want to use jquery.
Bootstrap is one of the modt popular libraries to make things look good easily on your website.
For js there is also electron.js for building desktop applications using Javascript HTML and CSS.
Additionally you may also include APIs into your frontend - for example Google Maps, Adsense, YouTube...
For PHP you normally use Frameworks that deal with the repetitive tasks on the server side. Laravel is one of the most popular PHP Frameworks.
I worked with Python and Django - a framework for python before - and I certainly enjoyed that.
IE is not a Browser that is targeted anymore by websites - instead of the standard Javascript it used its own language which is similar to js but does lack many of its standards. You often need to write completely new Javascript code for IE. You probably shouldn't expect any website to work when you use it.