Git hub Pull request question

I have created a fork and from that one a pull request

It seems to me that everything I commit in my repository is added to this pull request. Am I understanding this well? If yes how can this be stopped?

Create another branch of ‘develop’ branch.

Ok so this is the solution, create another branch…

Now regarding the cause… I think I should have not made the initial pull request out from my “develop” branch in the first place, but from a feature branch instead, right?

So the pull request was created from my develop branch.

After/If the pull request is accepted, can I delete my remote develop branch and recreate one with the same name? Would this new branch be independent from the existing Pull request?

Branches in your fork are your branches. You can anything with them.