Default First try at app development, a few questions

I've been doing my fair share of browsing, searching and reading, and I feel like I am off to a good start in getting my environment set up and installing all the correct software. I'm looking to create an app that acts mainly as a search engine but for some specific websites, what kind of coding knowledge do I need for this? I have the Android Studio installed and the interface for my app started, do I need a separate framework application for any reason? What are the frameworks used for exactly? I know (or used to know) some basic html, php, and visualbasic but how much that will help me now I don't know. Any help is greatly appreciated.