In terms of ease of learning, Python generally gets the nod for beginners. It has a really clean syntax that reads almost like English, which makes it easier to pick up the concepts. That being said, if you've already dabbled in VB.NET, don't discount it completely. For building desktop apps, VB.NET can be a great choice, especially if you're sticking to the Windows environment.
If you're brand new to programming, go with Python. It'll be a smoother learning curve for your first language. If you're set on building Windows desktop apps, sticking with VB.NET might be the way to go. You've already got some experience under your belt, and there are plenty of resources out there to help you along. As for your project - submitting URLs to websites sounds like something both Python and VB.NET can handle.