This tutorial by MVARTZ (Menno) is an excellent watch if you want to learn the concept of attributes. These attributes make Geometry Nodes very powerful. See these attributes as variables, or in other words dynamic values. Once you get the hang of it, you are well on your way mastering Geometry Nodes. Another thing you need to know is the different input types like attributes, float, vector and color. So I suggest to watch the video and every time MVARTZ explains about it, pause the video and do a recap for yourself. Then after the video, experiment and try it yourself. And soon you will be able to use Geometry Nodes and Proximity Displacement
Quick overview of the tutorial
Menno starts with a round cube and adds Geometry nodes to it. We add the nodes like Subdivision Surface and Attribute Texture Sampler. That is to displace the geometry with a texture. Next is an Attribute mix node, and that is to displace it on the normals. Because the displacement is to much now, we add another Attribute mix node. After this it gets a bit tough so you might stop the video and think about it. Namely, we use multiple displacements and that comes with some complications. It definitely worth it to understand this part, so take your time. What follows is the proximity effect with an empty and also driving some attributes in a shader. So it’s quite a complete tutorial if you want to go into Geometry Nodes and Proximity Displacement.
Geometry Nodes and Proximity Displacement video
Getting the concept of attributes
Below you see the first part of the node setup. What it does is, it gives a noisy displacement on the roundcube. An example of how attributes work: You see that in Mapping we used the predefined attribute position. This means that for every vertex the position will be affected by the displacement modifier. And the height is our own word-choice: we can also call it penguin. The factor is like a mix, so we mix the position of the vertex with normal by height. And that is the new position, so it’s an override of the old position. Get this idea first or you will get stuck later on in the video.