If I dont want a domain name now, I already have one, but dont want to point it to Hostony for now, ultil Im ready. whta should I do for signup? for profi plan
maybe later I want to change nameservers for my domain to here.

You need to put domain name in order form but you can update name server for it as you want. We do not force our customers to use active domain names with account.

I see. So how about if I get a free domain name when I signed up, and then somewhere down the line when I'm set up I put my old domain onto the same space as well and don't use the free one that I got?

is that the way to do it