The backend you are working on can also help narrow down what front end you may want to try. I am a “full-stack” .NET (i.e. I do backend but I’m stubborn enough to touch and make choices on our front end vs other members on my team). Naturally, our apps are ASP.NET MVC/Razor pages, and I’ve dragged a few things over to Blazor for some of our new apps. One could still add vanilla JS / Browser APIs on top of this and cover most needs. Bootstrap consider what you need to keep you app mobile-friendly (usually described as “responsive”), and can be used with just data- attributes.
My opinion is the front end should be quick and should also be light on business logic. Then you are just making http requests for data retrieval or requesting the server to do something. Then you can break out your backend methods/services to handle your data persistence > business logic > shaping the results for what your front end needs
Sorry that got long TL;DR see what front end usually seems paired with your backend and start there. For example, try .NET/ASP.NET Core
That seem reasonable. Don’t add more to learn before you know you need it. Is there an http server that is built in to Rust?