I agree with soonix that it's mostly a matter of terminology.

However, if you are asking whether you should have forked the original repo at github as was done or instead should have directly cloned the original repo to your local machine, then I would say the former. You need somewhere on github to store the branch with your amendments because you don't have rights to push to the original repo. If you want a local copy for testing (which is usually wise) then what you have done is the usual approach. You can either make your changes in the github editor as has happened here or perhaps more usually, clone your untouched fork and then do all the work on your local copy only pushing back up to your fork when happy. I generally find it easier to work locally using my own tools. YMMV.

Obviously, there's an awful lot more to it and this is just scratching the surface but you are on your way now so the sky's the limit.

It is also important to realise that github is just one SaaS repository. Others have their own ways of doing things so it would be wise/prudent to see how the process happens elsewhere. By all means leverage the tools which github provides but don't become dependent on them as they could change at any time (or you may become unable to use them for other reasons).