That feeling of staring at the screen and wondering if you belong is incredibly common, so do not let it discourage you. If you want to balance web and android development without getting overwhelmed, the best foundation you can build right now is JavaScript.
Learning JavaScript well sets you up for the web, but it also opens the door to React Native, which lets you build android apps using the exact same logic. It saves you from having to learn two completely different programming languages at the same time. The best roadmap is to stick with HTML and CSS until you can build a basic page layout from memory, and then dive into JavaScript. Expect to feel confused for a few weeks, but if you keep writing code daily instead of just reading it, the logic will start to click