Monopole at 900 MHz in HFSS

Hi,
My name is HANAN. I m doing a PROJECT of ANTENNA THEORY.I want to design MONOPOLE at 900MHz in HFSS. I m new with this simulator So plz can anybody guide me from where should I start. Plz help me guyz i need this urgently.

in this post there are many examples such as monopole.hfss that can help you:
https://www.edaboard.com/viewtopic.php?t=286045


in this post there are many tutorials on hfss that will help you:
https://www.edaboard.com/viewtopic.php?t=157258

Hey Thanks for the help.
Can u also tell me what parameters should i have to calculate for it?
I mean Input impedance,Directivity,Length. etc. Also which boundaries i have to select for it?