First time using GIT

Hi everyone, this is my 1st time using GIT. I am currently following the steps over here: Django Tutorial Part 11: Deploying Django to production - Learn web development | MDN

After following and installing. I got the error:

To https://github.com/CalvinTheCat/test1.git
! [rejected] main → main (fetch first)
error: failed to push some refs to ‘link’
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., ‘git pull …’) before pushing again.
hint: See the ‘Note about fast-forwards’ in ‘git push --help’ for details.

Can someone help me? Thank you

This is the key part:

Updates were rejected because the remote contains work that you do not have locally.

What to do depends on whether you want to keep or discard those changes.