Click explore,then under commerce center there should be a link called soul market, click it, then buy how ever many souls desired
Chat with our AI personalities
you can sell them to the soul collector or put them on the soul market
yes
Immortal night is a website where you can choose vampire, or Lycan (Werewolf) I actually have an account as sylavela on there, and I would be glad to help you if you have any more questions. : )
You should check in the shops where you find everything else you would want to buy.
Demon Souls is the 1st of the series, with Dark Souls being second. Storyline wise, Demon Souls is also before Dark Souls.