Having a private branch of a public repo on GitHub?

Question

I have a public PHP project in a GitHub repo, which contains just one branch (master).

I want to have a separate branch/fork that is private for me (I have paid for

Answer 1

1.) Is it possible to have a private branch on a public repo

From what I know, no.

2.) Can I fork my own public repo into my own private branch

No, you can't fork a full repo (1-n branches) into a single branch. Well actually you could, if you just fork the one branch of the full repo. Just add it as a remote or start from a clone.

You might also be interested in Sparse checkouts.

3.) If both the above the are possible which is the best way forward

n/a

4.) If neither are possible how should I proceed?

n/a