Loading rgb iamge and .ply file

I am very new to 3D Slicer, and I would appreciate it if someone could help clarify my understanding regarding the following query:

I have a .dcm file that contains an RGB 2D image and metadata for all modules such as patient, series, etc. I was able to import two files i.e. .dcm file and a .ply file.
In my .dcm file, I am using the SOP Class for Surface Scan Point Cloud Storage, and I still need to figure out the values to populate this class’s attributes. When I import my .dcm file, it is successful, and I can see my metadata along with the RGB image. However, when I attempt to load it, I encounter the following error “Reference image in series does not contain geometry information. Please use caution”. Consequently, I am struggling to determine whether I should first learn how to load a 2D RGB image on 3D Slicer or focus on filling in the values (note: I am new to DICOM and still understanding different SOP classes).

I have also created a .ply file containing point clouds of the RGB image. I would like to know how to overlay these point clouds on my 2D image using 3D Slicer.

Alternatively, if there is any test data available that I can use for practice before applying it to my own image in 3D Slicer, I would greatly appreciate that information.