VB is easier to get started in than other languages. It is
relatively simple and straightforward. C++ is much harder.
Delphi is a bit harder, but IMHO its strong type checking
make you learn better programming habits so it may be a better
first language to learn.
As far as limitations, you can do pretty much anything using any
language. Delphi and C++ are faster than VB because they
produce compiled executables while a VB program must still be
at least partly interpreted at run time. For a CPU intensive
program, those languages can be as much as 5 times faster.
The programs are also smaller and do not require run time
libraries like a VB program does.
On the other hand, if your application is limited by database
access speed, file processing, displaying a lot of forms, etc.
then a VB program may be as fast as the others and will
probably be a lot easier to build. And these days programmer
time is relatively expensive so it's often more cost effective
to buy a faster computer than to write in a faster language.
Finally, learning VB can give you some extra leverage with
Microsoft Office applications and Web programming. VBA
(Visual Basic for Applications) is a flavor of VB used as the
macro language by Word, Excel, Access, etc. VBScript is another
almost identical flavor used for building dynamic Web pages
and ASP (Active Server Pages). So if you know VB, you also know
these others as well.
Overall I like Delphi, but VB has some strong advantages.