From PC to Mac?

Hello

I’m trying desperately to get my Cubase started on my mac. But I’m not getting anywhere.
I used to use cubase on my pc, but now I’ve got a mac, and I have absolutely no idea of what I’m supposed to do.
I’m not at all at technical genius - not with macs, not with cubase.
I know my Cubase product is mac compatible - but how about the midikeyboard and the fast track M-Audio?
I can open my cubase, implement halion and so - but I can’t hear any sounds?
Hope there’s someone out there who can help me?

Thanks, Molli

MacBook Pro
Cubase Essential 4.1.2
M-Audio fast track
Edirol Midi keyboard controller PC-50