我正在尝试推送我的项目（新存储库中的所有文件）。我按照这些步骤进行操作，但是当我推动时出现git push -u origin master此错误：

! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to 'git@github.com:asantoya/projectnewbies.git'
To prevent you from losing history, non-fast-forward updates were rejected
Merge the remote changes (e.g. 'git pull') before pushing again.  See the
'Note about fast-forwards' section of 'git push --help' for details.

我多次收到此错误，无法弄清楚该怎么做。