to - is used to move from point A to point B

at - general place - at home but in the kitchen,  at the mall in the Sephora store, at the cinema in room A, at Nestle company in the Felix conference room

at the intersection of Aleje Jerozolimskie and Marszalkowska 

In - means inside some sort of a border,  ex. the water is in the glass/ I live in Warsaw.  

on - surface ex.  the books are on the table, the painting is on the wall, the lights are on the ceiling, my feet are on the floor