The a blank revit file is pretty sparse, best to use a template.
Have you been able to get the direct shapes to load without any warnings? That’s the place to start. Then you can create a new file and start creating more specific families as you need to from the geometry you know that works.
Feel free to ask questions, just try to be specific and along the lines of the grasshopper sticky where you create a new topic that others looking for the same issue might be able to find in the future.