install git at you laptop

https://git-scm.com/downloads

config git at you laptop

git config --global user.name "Your Name"

git config --global user.email "email@example.com"

git config --global core.autocrlf false

git config --global core.safecrlf true

add a project at github

New a project at github

git clone project at laptop

git clone github repo address

open project at atom

package - github - Toggle git tab

select a branch

edit the files

git commit

git push