Implement LAN and SAT in a single-family house with a central server cabinet

Great things when money doesn't matter. Everyone sets different priorities, in the end everything works.

... with companies and craftsmen, it often looks much worse...

Proper planning is important. Otherwise, you will only get annoyed in the end and can only improve it with considerable effort and/or visual impairment.

I suspect your comment refers to my setup. That is certainly not the standard for a single-family house.
Certainly, I have different demands here and indulge a bit in my technical playfulness.
However, there were some very sensible suggestions here. No one said that everyone needs a 10GB router and network.

There were some very sensible suggestions here. No one said that everyone needs a 10GB router and network.

So far, I have been able to gather great information and ideas here.

I would like to revise my planning for the network.
A question regarding this:
Is there a suitable tool that can, for example, directly tell me how many meters of installation cable I need, how wide the passage in the server cabinet must be for all the cables, and create a proper plan for me?

Since we're already talking about sense/nonsense here... I briefly considered laying fiber optic cables in the house during the planning phase, as preparation for gigabit from the provider. Now, network cards for PCs are quite expensive, as are the necessary adapters for consoles, TVs, etc. Not to mention the extra cost for the cables and technology. I'm leaning back towards CAT7 mentally to avoid blowing the costs. Has anyone had similar thoughts or is that totally off the mark? It's certainly not a standard, but as soon as a NAS or even a home server is added, the FritzBox quickly hits its limits when multiple parallel data streams are involved. Then it's better to have a switch where the internal traffic goes through and only the internet goes through the box. Just for that alone I would at least get a small switch.

So... I have given it some more thought.
All the little experiments that have been suggested so far, I find all of them very interesting.
However, at the moment I am not willing to invest too much money and especially planning time into "fully planning" the entire network.

I would rather approach it so that I lay a good foundation and prepare the system so that I can expand it later as I wish.

So initially it’s about the foundation of the network, which I have to plan and implement during the rough construction phase.
Therefore, I would like to proceed as follows:
1. Plan cabling. Designed for a total of 24 connection points.
2. Each connection point to be served with duplex patch cable.
3. Connect a double network socket to the connection points to be used from the start.
4. Position a network cabinet.
5. Terminate the patch cables in the network cabinet on 2x24 patch panels.
6. Cable the (occupied) ports of the patch panels to the switch.
7. Plug the Fritzbox into any port of the switch.

From that point, a basic network should be established, right?

I can then expand this at any time with access points, new (larger or better) switches, etc. If I need a connection at one of the prepared points, I just open the outlet and connect a double network socket to the corresponding duplex patch cable.

My questions before I go into the hardware details:

[*] Have I understood the situation correctly?
[*] Can I simply leave network patch cables in the wall outlet unconnected and terminate the other end on the patch panel, or is that not advisable?
[*] How and where should I plan the access points in our floor plan (2-story without basement) in order to cover everything?