If you just want to get points from excel to rhino it is simpler than writing code. Although writing the code will help with learning for other uses.
- In excel, fill in columns for x, y & z data
- Create a single column with concatenation of the coords into “x,y,z”
- Copy the column of “x,y,z”
- In rhino, start the “_Points” command
- Paste
The extension to this that can be achieved with rhinoscripting is that you can assign colours, names and layers to the points so that it is easier to group them for developing your curves and surfaces later.
There’s also this method.