My mom has a windows phone, and I have not even been able to figure that thing out... Not to even figure out where the apps are.
I'm going to help you out here.
Put the phone in you Left Hand.
Take you right hand and put it on the Main Screen.
Move your finger Left.
Magnifying glass on Top Left if you want to search.
Number or letter block if you want to just jump to an area.
Hold Finger on the Icon to bring up the menu to pin, uninstall, send to kids corner, etc.
Now that we're in where all the apps are hit the nearest latter.
Pick S.
Scroll down to Store to get more apps.
That's the really basic. Settings has more. Like you'll probably want to turn Battery Saver on so it goes into Heart Mode when the batter is low.