Snowboards differ in construction, shapes, stiffness and performance, not just graphics.
Getting a board too low in performance will chatter and loose edge control. Too high performance will make it difficult to turn. Getting the correct performance will allow you to progress rapidly and have fun while learning.
Did you know your snowboard length is determined by your weight and not by your height! Many manufactures put sizing stickers on the bottom of their board to help you get the correct length. Getting too short of board and you can loose control. Getting too long of snowboard can make it difficult to turn so make sure you get the length the manufacture recommends for your weight.