At first you should figure out what do you want to create, make plans and set requirements. Planning comes first and implementation follows. Tools (and the selection of tools) only matter in the light of a problem: if there's no problem to solve, why would you need any tool anyway? Also I'm not sure about what you mean by "beautiful". Visual design and aesthetics is an entirely different field. To learn about that visit an art school. :)
On the choice between PHP vs. Node - I'd recommend learning Node. A good grasp of JavaScript is a more versatile skill to acquire since you will use the same language to write the client-side code too. In fact, making a web app isomorphic is a very interesting way to provide great user experience! Here's a good article on the topic: What is an isomorphic application?