As a beginner, you won't be building anything big, probably. Focus on learning the stack, the language, MVC. Get to know the libraries. When you are comfortable with that, learn how to test.

Now, I believe 100% test coverage is plain silly. There are things you don't really have to test, and you are the only one who can tell.

I just started building a new app, and haven't done any testing until I was half-way through the first iteration (what I considered to be my first public alpha). I wrote a few tests to make sure the functionality I'd implemented would still work when I changed the code, then I moved to a more TDD dev style.

I wrote a few (maybe 10) tests for things I wasn't sure how they'd behave, noticed I could fix some of my code.

So, TDD can help you, for sure. But don't get too caught up in writing tests if it's getting in the way of actually writing your code.