the best thing i can tell you is to buy the install video for the product you purchased.however in general terms these planks are aprox 12" x 48" and show 4 tiles.start at the longest wall and install the 1st full row,for the second row cut off one tile.(leaves a 3 tile piece)for the 3rd row cut off 2 tiles. so for the first 3 rows your end joints are staggered,the 4th row go back to a full piece,and continue across the floor the way you did the first 3 rows.
the next thing to concider is ,if the tile will end on a 1/2 tile or less,so measure the width and length of the room and if need be cut some off the first plank,so the room will be balanced.......good luck