There is no real difference except syntax. The .NET Framework provides all the objects you use, so a TextBox behaves the same way and has the same methods and members in C# as it does in VB.NET. It's simply the syntax used to manipulate them.
If you have a background in C-like languages (especially Java) you'll find C# easier to adapt to. If you have a VB background like VB6 or 5, you'll find VB.NET easier. If you have no Object-Oriented experience, you'll have a bit of trouble with them both until you understand the concepts behind objects. I've heard that VB.NET is easier for beginners because the language is simpler, but I like C# myself. Seems easier to do things in less code, and more flexibility. But that's just my experience.