Hi 
It is overwhelmingly complicated when you first look at it!
Luckily most of that stuff is for the devs or QA Team. So you really kinda
ignore all the drop-downs and stuff and just focus on the bit that looks
like posting an email = the subject-line and then the message-box under
it. It is tough trying to pick a useful subject-line that avoids the words
LibreOffice or bug and that quickly make it obvious that you are reporting
about something that is different from all the other LibreOffice
bug-reports.
The wiki-guide asks for tons of info and logs and such but these are things
you can add later. The QA Team can even help you figure out how to post
the logs and such so the main thing is that first posting in the
bug-reporting thing. Once you have done one you'll probably realise how
easy it is and probably soon find yourself helping other people post a
better report or add useful stuff to their reports too.
It's just that when you first look at it there does seem to be a
bewildering amount of complexity but it's actually much easier than it
looks.
Regards from
Tom 