Building WordPress website on my own PC

I already have a working WordPress site and I want to build a second

Preferably, I want to build my website before transferring my domain to the website host (Hostpapa).

However, Hostpapa seem to have difficulty accommodating this reasonable request so I am trying to build the website on my PC but cannot get WordPress to work.

Any suggestions?

The site http://www.marchesdigital.co.uk is on Moonfruit at the moment and built using their supplied package. I just want to get out!