You will want to look at where your project files are in a view of the directory structure. You will want to look into your files to see what they say inside; like the code to do things. And you will want to run things from the command line or terminal. An integrated development environment has these things and more in one spot on your computer screen.
There are a number of IDE’s out there. One that is very commonly used is VSCode. It is available for free. And it has both a ‘put on your own machine’ software version and a version that is simply run in a browser without you installing it. It is comfortable to work in both because they are very much mirror images in look and feel. The nice thing about the locally installed copy is it works with a copy of your project on your own computer so it is fast. And integrated with Git and a GitHub repository a hosted copy is out there in case you are working on a computer other than your own and want to use the browser version.