Directing New People to Sign Up

OK this might sound like a newbie question :slight_smile: so bear with me here. I am a bit confused as to the process by a which a new person would come online and sign up and then pay for my pro version (I installed Pro Sites).

So, on my website when I tell people to "Go Sign Up Now" what page should I be sending them to? Do they pay first and then get redirected to fill out their website info, or do they need to fill out the website info first, and then they get redirected to pay? I think if I could understand this a bit better I will be better off understanding how to set up my pages. Thanks..