When useing impress, how can I find the mode, where I as a teacher can see my notes under the page on the screen, but the watchers don´t?
It will appear when you use two screens, I do not know if it possible to use this mode only with only one screen
you can use Presenter Console if you have two displays. On your laptop (for example) you’ll see your Notes and on big display you can show the slide show
https://help.libreoffice.org/6.0/en-US/text/simpress/guide/presenter_console.html