Loading and printing files

I have just started using this beautiful program. I have drawn a mechanical item but I cannot print it: the preview is blank and the sheets come out blank as well  from the printer .
In addition, I cannot load the file I made into the program  when the program has been started  from the  app panel of Windows11, though the file  appears when clicked on its icon  of Windows11 Explorer together with LibreCad  but, in this case, the  upper  bar of the program lacks the help panel.
Thanks in advance for some  kind help.

Sheets blank: often the reason is linewidth "By Layer" is set, where default is 0.00mm. Depending on printer often not printed at all, or very very faint. But as you say -
Preview blank: preview shows linewidth 0.00mm, so it must be something different. Maybe out of the sheet, or very small. Try the buttons "Fit to page" and "Center to page", also play with the scale setting.

- Cannot load file I made - from within the app: There have been complaints like this with Windows in the past, but I don't remember the abouts, what's the reason and how to fix it. You may have success with using File - Recent files.

-When opening file from Windows Explorer the help panel is missing: I have no explanation, you may try Options - Application Preferences - Defaults - Clear Settings - Layout or All, in case you have borked something.