Cubase is more of a digital audio workstation that allows you to record, edit and arrange music more than DJ.
I'd invest in some hardware to get you started. Perhaps you might consider the CDJ / DJM 350 setup or even the 850 setup if you can stretch your budget that far.
We've no way of telling you if the music you are creating will be suitable for a club. What is club music in your area? Ultimately, you, as the DJ, will decided what club music is - its the DJ that is creating and catering to the musical tastes.
Yes, big name DJs play tracks that they have produced themselves as well as other artists tracks.