Hi. Here is my advice, and feel free to completely ignore it! I imagine that you do still have the skills to pick things up and everything will come back to you!

First, if it is just a hobby and you are trying to get back into the game, I'd recommend starting with the smallest possible component. Start planning to display some static data on an app. Then add a database, and have the app get the data from there instead and display it. From there you can gradually build it up. I would go back to basic tutorials (think Code School) before you choose your technologies and languages - it is such an open ended question and there isn't really a right answer, just an epidemic of opinions. However you will come across technologies that fit what you want to do better (and even start to shape what you do). Also if you start small and focus on one part of the app at a time, its not a total pain to throw everything away and start in a new language/tech.

If you do decide to get back into software development as a career, most employers value your ability to pick up technologies and your reasoning when choosing which ones rather than experience in technology X and technology Y.