As far as Brackets, I haven’t used it. I find it odd that a code editor would default to using smart (curly) quotes - in general dumb (straight) quotes are going to be much safer. I’m sure there’s some in the settings you can change.
With regards to codepen, none of the frontend projects really require uploading files - I’ve just used the free service. It just will make it so much easier if you need help for us to actually see what you are doing and make changes and see the results. There have been times when I see questions with three pages of code listed that I’m supposed to read through and I just skip it because I don’t have time to set everything up to run it.
Are you required to use codepen? No. But you’re eventually going to have to share it when you finish. There are other options, but codepen fits the bill and many use it. And it’s easy to export from codepen to “the real world.”
True, codepen has its limitations. It’s great for small little projects where you can fit everything into one file. But until you get to the backend, it works great for the FCC stuff. Eventually your personal projects will get too big for codepen, but I still use it for quick and dirty testing things out, especially JS algorithms. It’s great for that.
But it’s up to you.