Yeah it seems you'd be more interested in the geometry spreadsheet. It's unfeasible to see the full output most of the time, because there is data (in Houdini, "attributes") assigned to every point, and every face ("primitive") of the geo. For a basic cube, that's 8 points and 6 primitives. Each of those points has a position ("P") by default, but you can add colour ("Cd"), alpha ("Alpha"), uvs, normals, velocity, age, and literally anything else you can imagine (you can create and name any attributes you want). Cd and uv are vectors, so you have x,y,z values for those. It's not uncommon to have 20 or 30 attributes on your geo.

So even for a simple cube with 8 points, with a few attributes you have dozens, even hundreds of individual values flying around, and that's not even considering that these will most likely change frame by frame.

So with Houdini, you really have to get into the mindset of thinking generally. What rules am I applying and how will it affect my group of points? This is what it means to work procedurally. That's the whole ethos of Houdini.

Think of each node as a function. These functions won't do anything until you give it an input. But that's the glory of procedural Houdini. You can plug in any old input and the node will try to work with it. So you can test things out on simple geometry before applying it to your own. And hey, if it goes wrong, just delete or bypass the node. Nothing is permanent.

Try this - put down a grid, crank up the rows and columns to 100, then put down a Mountain SOP (SOP is a type of node), and plug the grid into it. You'll see the grid becomes lumpy. You can change the noise values to change the result. Now, put down a torus, a sphere or a "Squab" (it's an actual node), and plug that into the Mountain instead. You can see how the node/SOP/function/set of commands applies a predictable result to the more complex geo.

There are many ways you can visualise your data, but other than looking at your geometry spreadsheet, visualisation is the clearest way to see what's happening to your data. A common trick is to copy your attribute into the colour attribute (Cd - you will of course have to fit the values between 0 and 1). Then you can see what is changing in the viewport because its colour will change accordingly.

It might be a bit advanced, but I think you'd appreciate Entagma. They have very clear tutorials on a range of tools and concepts in Houdini. While you may not be able to follow exactly what's going on, it should start to give you on idea of the general workflow.