You won't get into trouble for posting a lot of help requests - that's how we all learn.
To make the AI "blow its horn" you will need to put a whistle object on the track - they work like signal objects. In the real world these were actually track signs that had a big "W" or the word "Whistle" on them and they can be found in the track objects tab - but some of them are decoration only, they do not force a whistle or horn sound.
One that I use that does work is called "Whistle Board" and came with the TR12 installation, but there are others.