How to change html content of a webpage with its URL using Node.js and JQuery?

I’m a beginner in node.js so I’m trying to change the content of my index.html but i don’t know how to change the URL of the web page along with it. Do angular.js allow this kind of stuff or i can just do it with node and jquery.

So i have a homepage with few lines text and some anchors(“Log In” and “Sing up”) which whenever one of them is clicked, i hide the homepage with jquery and show the corresponding form (login to Login form and signup to signup form). But my problem is that i want also to change the URL along with it so that i can use it with express.js to do some other stuff, but i didn’t make it. I searched about it but i didn’t find any answer. I found something about “history.pushstate()” but i didn’t understand a thing.

I’d like to get an explanation, if possible, with the solution. And if it has anything to do with the history object, please simplify it because i didn’t understand anything when i searched it.
If possible, can you give some tips to clean my code and organize my files. Finally, can you tell me what is that ‘package-lock.json’ file, it showed up when i tried to install express.js in node.js without the command “–save”.
Please, can you tell me also how to create multiple webpages, should i create multiple html files or not, if yes then how to link them. If no then in a single webpage application, how do we change the URL when we change the content of the html.

Thank you in advance