Start with JSP backed by logic in Java classes. Or use servlets.
The advantage of using JSP and Servlets is that you gain knowledge of what all the frameworks do under the hood. And that understanding is crucial to figure out how to do X in that particular framework.
Furthermore, JSP is very easy. You can easily see what you're doing and very easily see it when you mess up the view with business logic.
And quite a lot of frameworks (Struts, Spring MVC) use JSP as their view technology. It's a natural first step in web development using Java.
