[karmakaze]

How dynamic does your webapp need to be? Can it do it's main function and provide value with back-end rendered HTML? If yes (or mostly yes) building that way will be much faster to test your idea. Some AJAX can be used as necessary.

If you do need (or simply want) to use a front-end framework, I would pick Vue.js as it's designed to be 'gradual' and so has a smoother learning curve. I suggest using single file compoonents (.vue extension) with properties and events and go without a central shared state.

Historically, React has been more popular and has a bigger job market. e.g. I use React at work and Vue for personal projects. I can't comment much on Angular other than the 1.x/2.x+ split isn't great for googling answers and many Anguar apps I've used are slow.

"Focus on product" as @maxxxxx puts it is the best advice. Work backwards from a goal. E.g. I want to release a product with x,y minimal features by z date on Product Hunt. Try to get others' hand on your app to get feedback and drive development based on usage/needs.