Sublime web project live update in browser

My Mac OSX 10.11.2 is running ST2 which has a web project with its related files and folders. I need to open the index.html in a browser and navigate from my project.
I learned after a lot of online reading here by John Papa that I need to run a local host, but following his step

Right click in Sublime and Open in Browser

which I understand as "right click on index.html and click Open in Browser", did not show such an option in the context menu, which lead me here by Thoriq Firdaus which requires installing the package SidebarEnhancement, which requires ST3 as indicated here in GitHub which is currently in Beta as indicated here

I also read somewhere about running $gulp from the terminal. I am really all confused.

What are the differences and when to use what? How can I run my web project in a local browser?
How can I update pages inside the project and the browser updates automatically?

Please help turning the lights on :)

Thank you