Thank you, guys :-)

tsquare: Make certain that you have a good understanding of the basics. It will be much easier to control what you intend to create.

Basics like:

1. Nodes:
   -Knowing how to create a new node.

• Understanding the difference between nodes outputting a number and nodes outputting a vector.
  -  Understanding the difference between a noise node and a fractal node.
  -  Knowing what filter nodes are and what they are good for.

2. Connections:

• Knowing how to make connections from one node to the next, and also how to connect a node to a parameter of another node.
• Knowing how to disconnect and reconnect.
• Understanding that a function needs to be connected to an  input node and an output node.

3. Parameters:

• Understanding what effect gain, roughness, etc have.
• Knowing how to influence a parameter by connecting another node to it.

Another advice I can give is to experiment with simple functions, just 1-3 nodes, and to find out what effect each parameter has. Also, try to create your own (simple) functions and play with the parameters and connections.

...and as Monsoon mentioned already, the function editor tutorials from Geekatplay may help you to get familiar with it (I found them really useful).

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