I am currently trying to setup Git for a project I have been working on for a while. I do remember quite a while ago setting up Git but never used it for various reasons. No
Instead of
git init git remote add origin https://USERNAME@bitbucket.org/USERNAME/APPNAME.git
you should use
git clone origin https://USERNAME@bitbucket.org/USERNAME/APPNAME.git .
since you want to clone an existing repository and not re-create it.