PWA-first web development recommendations?

• Syncable database across multiple devices, yet work offline
• Not every has to be JavaScript, with Web Assembly? (I prefer Golang, BTW)
• Best JavaScript framework, if needed, for conveniences
• Monetization

I already have a web app, BTW. https://zhquiz.cc If possible, I want to get a marketing coach; although I care more about sustainability, rather than profit.

It's Nuxt.js with @nuxtjs/pwa, BTW.