Hello everyone, I'm pretty new to NetSuite and I'm trying to figure out how to override a NetSuite module file using plugin method or PluginContainer for 2018.2 version. If someone can also point to the right direction or docs will be great too!

Hi! The PluginContainer module is for injecting HTML into templates at various stages of compiling and rendering. This doesn't sound like what you want. Furthermore, in 2018.2 we strongly advise against overriding module files, especially if you're a newbie. I would recommend making your changes through extensions. See developers.suitecommerce.com for help getting started