I really need info about Nokia developing. Can I program Nokia (Symbian) devices only with C++, or I need Qt too? (I have Nokia Qt SDK). I'm not really sure about GUI programing, so I ask for help :)
Also it would be really helpful, if you could tell me how to make something like cmd-style on Nokia (Symbian) <--(this is an optional question)
There are probably multiple ways to accomplish what you're trying to write (as Bala.C pointed out, you can use java), but the latest releases of the symbian OS have really encouraged people to write with Qt and specific with QML. That will likely have the fastest and smoothest interface to the device, because they've spent a fair amount of time optimizing it for the platform. Plus it'll make your application more portable to their N9 and other Qt based phones (the yet-to-ship non-windows Lumia).
I'm sure there is likely an API to tie directly into their lower-level architecture for drawing on the screen as well, but I suspect it's both not-well documented (unlike Qt) and subject to change from release to release as they don't expect developers to be using it as much.