git clone <addressoftherepo.git> clones the repository to local.
git add * is a similar command that adds all the file
git add filename.xyz tracks a file
git commit -m "message" for commiting the changes
git push to send changes to git repository
git branch to list all the local branches
git checkout for switching branches
git checkout -b <branchnew> creates a new branch called branchnew
git checkout <branchab> takes you to branchab
git checkout <######> where ###### are the first 6 characters from a commit log, takes to back to the time that commit was made
git merge <branchxx> merges content from branchxx to your current branch
git log branch specific, shows commit log
git status for status of the work in local
git branch -d branchname for deleting a branch
Use the Fork button on GitHub to copy another user's repository to your GitHub. Clone the repository to local and go about usual business of adding, commiting and pushing to make changes to your copy of the repository.
For syncing with the original repository, check
git remote add upstream <linktooriginalrepo.git>
git pull check to make changes to local branch from a remote branch
If you are tired of typing your username and password each time you commit, check this