Hey ttarekabdelhafez,
Good question,
Geometry nodes are still reasonably new in Blender, and still subject to change,
To produce an in depth course full of CGCookie goodness on Geometry Nodes takes time.
When Geometry Nodes are more consistent and stable in terms of production,
CGCookie.com does have plans to release a long awaited scrumptious GeoNodes course.
In the mean time check out the CGCookie YouTube Channel.
There you will find several GeoNode tutorials available.
Including:
Pots and Vases made in Blender - Geometry Nodes
3 Node Recipes To Get You Started In Blender Geometry Nodes 3.0
And lots more amazing content.
Happy Blending!
@jlampel, any update on a GeoNodes course?