This is a bit of a broad question, but is there a proper structure to UE4/Rocket projects? I am having a hard time understanding what a .uasset is and how I properly open it in the content browser. Do I need to have it in a specific folder in the project?
Tom provided some great information but let me see if I can shed a bit more light. A .uasset is the generic extension for a piece of content in the editor. So for example if you import in a image for a texture say example.jpeg it will be put it into your project as a example.uasset; Same for static meshes and so on. Now there is no way to import it while in the editor. You must do what Tom said and copy the .uasset to the content folder of your main project folder. This is the auto-generated folder that gets created to store and organize all your assests.
If you are loading a .uasset from, say, the tutorials, you should put it in the project folder for the project you are opening in order to for it to self-populate in the Quick Browser. At least that worked for me…
By default Projects are created in user/my documents/projectname
You can check which project is current, therefore showing its assets, as shown here: