Hello everyone.
Hope you are having a nice day/evening.
As you may have already noticed from the title/question, I need a lot of help in understanding how this works.
Basically, I work as a freelancer and I had a client who needed me to make some changes to a website. Till now, I've only used the old fashioned way and never used before git/bitbucket.
They sent me a link to a repository which I cloned and they gave me access to the online version as the website it's running on WordPress.
My issue here is that I don't know how to make the changes the client asked me to, via SourceTree App.
Am I supposed just to say what am I going to do "commit", paste changes to file or CSS code or what... 
Does anybody happen to have a tutorial for dummies like myself so I can start working and make the changes on the client website?
Thank you very much for taking time to read this.
Any suggestion will be much appreciated.
Regards.
