First of all, I'm not sure "Other Languages" is the right sub-forum for this. I think "Other Languages" is for other human languages, not programming languages.
Second, I'm going to assume you're running Raspbian. If not, adjust accordingly.
That said, the best first step is to do:
$ apt-cache search mono | grep "^mono" | less
And see what is available. I see something there called "mono-complete", which is probably the best thing to install. There is also something called "mono-vbnc", which implies that VB.NET is supported, so that's good.
After having installed something like that, I'd then go to my Windows machine and write a very simple "hello, world" type program in VB.NET, compile it to an EXE and then bring that EXE over to the Pi. On the Pi, you should be able to run it via something like (I'm guessing here, but I'm pretty sure this is how you do it):
$ mono hello.exe
And it should work.
Once that I had all that working, I'd be up and running...
"L'enfer, c'est les autres"