Getting started, need to learn

Hello, this is my first post.  I've never modified any LibreOffice code, and the programming 
knowledge I have is obsolete.  Maybe someone could point me in the right direction of what I need 
to learn.  I want to modify LibreOffice Writer's macro feature.  Specifically, I want to add the 
ability to use Ctrl+[two letters] in the form of these hot keys: 
Ctrl+QD
Ctrl+QS
Ctrl+QR
Ctrl+QC
Ctrl+KS
Ctrl+KD
Ctrl+OS
Ctrl+QL
Currently in LO Writer, you can only add Ctrl+[one letter].  If I added only those hot keys shown 
above, that would be enough.  I wouldn't necessarily have to add the ability to add any two 
letters.  

What programming language do I need to learn to accomplish this?  Back in 2000 to about 2006 I 
programmed in MS Visual BASIC 6, which obviously is not the language used in LibreOffice and is now 
obsolete anyway.  

First, I need to add this change simply for my own use and see how well it works.  Second, after 
I'm satisfied that it works well, I need to find a way to share the change with others.  There are 
other people who want this change.  I'll need to therefore learn how to package this as some type 
of add-in that others can install.  I don't foresee the demand for this feature as being high 
enough for it to become an official part of LO Writer, though I guess I could be wrong.  

Third, I need to choose a language to learn for creating standalone Linux-based applications.  I no 
longer use MS Windows.  Not long after my upgrade from Microsoft Office to LibreOffice, I upgraded 
from Windows to Kubuntu Linux.  Even if the language I know, Visual BASIC 6, were not obsoleted, it 
would no longer be right for me as it has never been able to create Linux-based software.  I could 
go for Gambas, which is very much like VB and is free in the Linux repositories.  I could also go 
for Xojo, which is also a BASIC programming language a lot like VB and can compile for Linux, Mac, 
and Windows, but does cost some money. There's also C++ which is used a lot in the Linux community 
(and in Windows).  I've dabbled with it, but never became proficient in it.  Finally, I'm 
considering using Python simply because it's so widely used in the Linux community and a lot is 
written about it.  
To recap, I want to: 
1. Learn what I need to in order to modify LO Writer's macro hot key assignments.
2. Learn how to share that change with others.
3. Pick a language to learn for creating standalone Linux-based applications.