[meeera]

There's a sticky in this forum on how to use Calibre to create and manage collections on your Kobo. This works beautifully (if you follow the directions correctly).

If you know you're looking for a particular title or author, don't fumble through your entire sorted library; use Search instead.

Searching always works as it should for me. Make you you check the dropdown on the right to make sure you're searching your library on the device, not the Kobo store or the book you're currently reading. I'm not sure exactly what trouble you're having with search. Can you explain more clearly?

Without more information, I suspect that your problem right now is that you don't know how to use your device yet. That happens to everyone. Read and learn and try things out, and that will change quickly.