I goofed and wanted to help contribute to a repo I lack access to or don't own but I think what I did was in the wrong order. Here is what I did.
remote: Permission to Codenator81/ng2do-mean-app.git denied to me.
Yes, without push access, your only option is to fork the repo.
It doesn't matter whether you clone from the original and then fork, or fork and then clone from your fork. In either case, you'll have to add the other repo as a remote. E.g.:
git remote add upstream https://github.com/Codenator81/ng2do-mean-app.git
(I usually fork and clone from the fork, so that
origin points to my fork, and I can add
upstream as the original repo. Of course, you can still do it the other way and rename the remote with
git remote rename.)
If your changes are simple enough, then GitHub does allow you to edit files directly in the web interface. However, this is just a shortcut for the fork-and-clone process that you are doing (except that you don't have to clone the repo to your machine).