Use:

Planet Scale - Controls the scale of the planet. 

Subdiv Level - Controls the amount of subdivisions applied to the planet. 

Continent Scale - Controls the size of continents.

Continent Offset - Controls offset of continents. 

Island Scale - Controls the size of islands. 

Island Offset - Controls the offset of islands. 

Small River Offset - Controls offset of small rivers.

Large River Offset - Controls the offset of large rivers. 

Water Color - Controls color of water.

Water Coverage - Controls the amount of the planet's surface covered with water.

Forest Color - Controls color of forest biome.

Grassland Color - Controls color of grassland biome.

Desert Color - Controls color of desert biome. 

Desert Coverage - Controls coverage of Desert relative to other biomes. 

Forest Coverage - Controls coverage of Forest relative to other biomes. 

Atmosphere Depth - Controls distance from the surface the atmosphere ends. 

Atmosphere Density - Controls thickness of atmosphere. 

Atmosphere Color - Controls tint of atmosphere. 

Cloud Offset - Controls offset of clouds. 

Clouds Color - Controls color of clouds. 

Cloud Coverage - Controls coverage of clouds. 

Bump Scale - Controls the strength of surface displacement.

Known Issues:

Using multiple planets in one scene may cause Atmosphere Parameter's to become linked. This is due to a bug with Blender and will be resolved when the bug is patched. For now, you can circumvent this by going to the shader editor and removing drivers from the atmospheric material. 

When first appended into a new file, geometry nodes may not work. Restart Blender if this happens.