Hi 
It's unlikely that you are missing anything other than Base but it might be
awkward to access some of the others.
There are several other ways of opening blank documents. if you could try
one of these and let us know what happens that might help us figure out
what is going wrong. Hopefully it's just a case of getting the right
short-cuts sorted out.
1. One way of forcing it is to just open something you can open. Then go
up to the icon-bar at the top and click on the little triangle beside the
blue or green icon. This should give a drop-down list of all the different
modules/programs. Hopefully you will see the gold/yellow one for impress
there and clicking on that should open a blank(ish) document using the
default template.
2. You might be able to do something similar from the File menu and choose
"New" from there.
3. Another way is to open a document in either Calc or Writer and then use
File - Close
Instead of quitting out of the whole of LibreOffice this should take you to
the "Splash Screen" that lists the most recent documents as well as giving
a list of all the different modules/programs and allowing you to open any
of them but as a new empty document.
Please let us know what result you get with one of those methods.
Good luck and regards from
Tom 