Inventory Window

Good day to all people around this forum! I am a new Unity user and unfortunately I am using an outdated version of the engine (4.3.4) due to my computer compatibilities. I would like to ask you a very simple question. I searched the web for some tutorials on how to make a very basic inventory but it seems like all of these tutorials were made in Unity 5 by using Canvas. My question is how can I make a very simply Inventory window without using Canvas? I also noticed (from some videos) that by using Canvas the gui is positioned exactly where you want to place it regardless of the selected resolution. Could any of you suggest a method for making an inventory of any kind? I thank you in advance.

-Vincent