Java and .NET have nothing to do with each other. Java is a programming language, and .NET is a framework with it's own programming languages (C# and VB.NET).
C# is similar in many regards to Java, and many find it an easy transition. However, there is absolutely no prerequisite of knowing Java for learning .NET, and you will never use Java at all while programming in .NET (unless you run into an old J# program, but that was used so very little that it was discontinued).
JavaScript, on the other hand, wouldn't hurt to learn if you plan on doing ASP.NET development (web applications). But again, it's not a prerequisite to learning any of the .NET languages or libraries.