HELP! me get a handle of the overview of this

I’m new to WordPress and experienced in web design.
The overall concept of how WP works is escaping me.
I have activated the theme swift because it sounds very capable.
but… how do I make it work? type in headlines and stories? add photos? I just need to know the overall basic concept of how everything works together and I’ll be able to take it from there… how do I get to my templates? use template tags?
someone help… please! -Gloria Justice