I don't want to use codepen

I tried to build my first front-end deb project on Codepen. I decided to start with the twitch api but working in codepen in my current setup drives me crazy. I have a laptop 12.5" with fairly low resolution screen and with codepen everything is in view at once. I spend a huge time managing my view/html/css/js windows.

I feel that Codepen works against me so my question is do I have to use Codepen? How about uploading the projects to Neocities,org? That way I can use a text-editor, a local server and a browser to work on my projects and can I separate everything neatly in separate files.