I was wondering if its better to create a shop with module scripts or local scripts because i want to learn more about modules even though i know so little on it. Thanks.
Creating your shop will be made with Local Scripts, as ModuleScripts don't execute when the game startups, And if you want to learn more about ModuleScripts, it's always nice to read this wiki page:
http://wiki.roblox.com/index.php?title=API:Class/ModuleScript
As you can see, **ModuleScripts **are going to be mostly used to define functions / variables that u going to use all along your game project. So that you don't need to write the function once again in a localscript, you can just call it with the requiered global function into the local script, having the module script with a defined function / variable in it.
ModuleScripts are mostly used for organization and a less repetitive development experience.
Hope this helped you on deciding what to do!