You need to be shown how to hold your hand, and you need someone to show you how to do the finger movements--the concept is very simple, so it doesn't take long for someone to show you, but it requires a lot of practice, meaning repetition, to get it down and polished--The personal demonstration (or, failing that, a good instructional video) is absolutely necessary--

Also, there are a number of different styles of finger picking, you should get them sorted out in your mind and settle on the one you want to learn before starting out--