ADS is not an intuitive program. If you want a software suite that is more "user friendly" to new users, then I'd recommend Microwave Office for your LNA design. That said, I use ADS a lot for my work, and find that it's a very powerful and flexible program. However, like Linux OS'es, it's very configurable, but sometimes that means you do a LOT of setup yourself and some parts aren't that easy/obvious to find.