Maybe for clarity if not self explaining:
The advanced/distant signal is used because the braking distance for a train is so long that it impossible to stop the train at the main signals on remaining distance when main signals becomes visible... I.e. It is a pre-warning to the lok driver for what to expect at next main signal.

OK guys.

Don't worry about it. Mike's got this.

Thewolf

Hope You are joking. No intention to insult antbody. English is not my native language so I may write something tha can be misunderstood🤭

Everything's fine. He was kidding.
Sometimes, when you see a question on this forum, just wait 24 hours before attempting to answer it.
Sometimes you will find that the issue was resolved outside the forum by Mike. And the solution will never be shared on the forum.

In other cases it is good to answer questions immediately on the forum so that other members can learn from the answers.
Sharing answers here is what this forum is all about.

As far as Mike and I are concerned, I would like to point out that in this particular case of advanced signals, it is impossible for me to share his solution, for the simple reason that he did not give me one, since these advanced signals will be installed on the top of the layout. He simply confirmed his intention to help me when the time comes, as I am still busy on the 1st level, the one of the hidden station.To finish, it seems to me that the relations on this forum are more and more difficult and I hesitate more and more to be active. This is an impression I have. If it is wrong, so much the better, but not long ago a member who intervened in this post told me outright that if I was not capable of doing the minimum manually in the world of HO railroading, I should refrain from doing this hobby. In real life, face to face, I wonder if he would have had the audacity to say that to me: I doubt it very much because his remark was disrespectful and deserved a very dry backlash

Signalling in real life is very complicated. On MRR layouts signalling will be more or less simplified.
The question is how simple or how realistic do you want to have it?
Since you opted for the 74391 signals I assume you want it strongly simplified.

Larger train stations have entry signals and exit signals.
There is a distant signal at every track leading to an entry signal.
There is another distant signal next to the entry signal that shows the state of the exit signal on the route.
There should be a distant signal at each exit signal showing the state of the next block signal on the route.

Entry signals are usually capable of showing Hp 1 and Hp 2, depending on the route that is set.
Exit signals are usually capable of showing Hp 1 and Hp 2, depending on the route that is set; sometimes on Hp 2 and Hp 00 are needed, sometimes only Hp 1 and Hp 00 are needed.

A simple approach would be having no distant signals at any entry or exit signals. But I'd recommend pairing the entry signals with distant signals unless the budget is very tight.

It's clear that you cannot share this information before you get it.
But for the benefit of others you can still share this information once you got it.