Some Basic Program in Various Languages.

Add the remote, call it "upstream" :

git remote add upstream https://github.com/vinayskywalker/Hactoberfest2020

Fetch all the branches of that remote into remote-tracking branches, such as upstream/main:

git fetch upstream

Make sure that you're on your main branch:

git checkout main

Rewrite your main branch so that any commits of yours that aren't already in upstream/main are replayed on top of that other branch:

git rebase upstream/main