Well, no-code is the gateway drug to code and I believe if you are investing time in learning this, it’s much more beneficial in the longer run to familiarize yourself with CS concepts.
WeWeb is only the front-end. It’s basically what you see and interact with. Xano is the backend. Yes it acts as a storage for your database and you can build complex logics too. It is definitely scalable and offers 100k records in the free plan. You may or may not choose Xano as a backend based on your requirements so do your own research on if it fits your use case/budget.
Start with the Level 1 of WeWeb academy that gives you a fair idea of what to expect when using Xano and WeWeb. Learn building UIs first using WeWeb by replicating available templates and figma designs. You can then watch WeWeb x Xano tutorials available on YT to start understanding the backend functionality.