Based on your requirements and resources I would recommend using plain simple JavaScript over any framework. The time you would spend learning any framework or build system would be better spent iterating on your core experience and experimenting with things that come out-of-the-box on modern web browsers. Frameworks inevitably drag you into their ecosystem where everyone marches at a certain pace. While there are benefits to this, I think it would be a distraction for you. Furthermore, there are many arcane JavaScript libraries that you may find useful down the road, and it is much easier to drag-and-drop them into your project with HTML "<script>" compared to fighting with module bundler du jour.