Compiler

If I am understanding your question correctly, a resource that you can practice your code with and that is actually on the website is the "Workspaces". Whenever you are on a video lesson that is wanting you to practice or enter code, at the bottom right corner of the video area, there should be a button that says, "Launch Workspace" in green.

Clicking on that button will open the Workspace for that particular video/lesson with all of the project files that will be needed so that you can edit it. These Workspaces are saved, and you can view/edit/delete them at any time by following the "Workspaces" link/button that is in the navigation area across the top of each webpage on the website. Different tracks will use Workspaces in different ways, and generally, there will be a lesson or two at the start of a track that will explain how Workspaces is used, and how to use it.

Workspaces work just like a "text editor", or IDE in that they have all of the project files and allow you to edit each file, and even delete unwanted, or upload new files. That way, you can keep everything right here on the website. You will get the hang of it pretty easily.

Also, if you find that you don't like the look or feel of Workspaces, you can always download a different text editor or IDE for whatever it is that you are learning to code. For website stuff, I use Brackets and Microsoft Expression Web 4 (which is discontinued but is free from the Microsoft website). For Java programming, I use IntelliJ or NetBeans.