将数据库添加到html文件最简单的方法是什么？

So I have made a project website with a couple html files, css and some javascript. I was thinking that I would add a login functionality and some other things like that. So I set off to find out what would be good for it. Now its is hard for me because I can't decide which one to use. I saw Django on python but I had to make a whole new project for it and I have to start from scratch. I was just thinking I would add a database to this site using something. I am just doing some lightweight things. What should I use? Thank you.So I have made a project website with a couple