Couple things: VBA is visual basic for applications... used primarily for Microsoft products like Excel. It's used primarily for writing macros. VB typically refers to earlier versions of Visual Basic that ended with version 6. It was a simpler programming language that many automation manufacturers embraced... it has been discontinued for many years. Microsoft released the .net platform to support many different programming languages under one common platform.

I've been creating HMI's with .net for years... it's very powerful in that you can talk to virtually any device via common protocols like rs232, rs485, tcp/ip, and USB. There are many other powerful features that would be hard to summarize in a post. The downside is that with all the capability comes complexity. There's a pretty big learning curve.

.net supports both visual and non visual languages... both have pros and cons. For HMI's, visual c or VB would be the way to go. The advantage to .net is that if you had a specific task that wasn't visual and was better suited to a non visual language, the two can be created separately and work together.

Microsoft provides visual studio community for free. Paid subscription is really geared for collaboration between multiple developers and deployment, you'll be able to accomplish everything you need for an hmi with community.

If you want to learn, start with some basic tutorials. After you take a few steps, start looking for tutorials more specific to automation and HMI's. There's a lot of people doing this, and you'll have no problems finding examples and references once you have some specific objectives.

It means "does not equal".

Equivalent c# operator is !=

See Comparison Operators (Visual Basic)