git init
git remote add origin https://github.com/CedricZhang9516/MuYield.git
git pull origin master

git add <file>
git commit
git push origin master

git log

alias gitpull='git pull origin master'
alias gitpush='git push origin master'

for the second and the following git res:

mkdir diffMu
cd diffMu
git init
git remote add origin https://github.com/CedricZhang9516/diffMu.git
git pull origin master
* when your github branch was named master