CAT cable in the utility room - not crimped?

I think we’ll put a cabinet on the wall. The cables are nicely long

Since you are still thinking and the electrician doesn't know the result of that thinking yet, that is doubly true. The difference between ceiling-high or floor-level in the cabinet is no small matter. Take enough cabinet depth to be able to rearrange later where the patch panel fits best. There is a wide variety of possibilities alone between wall racks, floor racks, and control cabinets. And you can't tell by looking at a client whether she is married to a business economist or a jet engine.

We are both IT professionals, but rather from the software side and less from the hardware side. I think we can manage to wire it up, I’m just missing the bridge between the cable without a head and the patch panel. I have never connected things that don’t have a plug yet, so I’m wondering what kind of intermediate pieces I need ([Keystone Modul], is that right?) and what tools I need to put such a head on the cable.

You only plug into the patch panel at the front, at the back it is firmly connected (with LSA+ for example).

take a photo if possible from straight on (of the corresponding utility room wall) so that something can be painted in showing how you (all) could optionally implement it.

you will be helped

take a photo preferably from straight ahead (of the corresponding utility room wall) so that something can be painted in showing how you (plural) could optionally implement it.

you will be helped

Thanks, I’ll do that tomorrow and post it here.

I just watched a video on YT, which was already quite helpful. Someone recommends a toolset with an LSA tool, a part for removing the insulation around it, and a tester to check if everything worked.
Then he shows that you lay the installation cable inside onto the patch panel, remove a piece of insulation, and then "punch down" the 8 wires inside one by one onto the patch panel with this LSA tool, so to speak.

There are 2 options.

1. LSA
You have already seen how it works. When working with LSA, you should definitely work carefully. It has always worked for me on the first try. This may be because I worked very carefully or because I use a branded tool (25€) for placement.

2. Keystone
I haven’t used it yet, but I would use it myself for the next patch panel. You simply clip the keystone modules onto the cable end, and when you’re done, you can clip the modules into the blank panel as desired. An LSA patch panel can be very bulky. It’s basically tool-free, but for some modules, a pair of parallel pliers can be quite useful.

The simple testers only ring through the line and only show the roughest faults. Either hire someone who has an expensive measuring device if you want to have it measured, or transfer a large file from one computer to another. If 125MB/s go through, then you have a GBit connection.