Installing on locaweb

Hello! This will be a long question, sorry.
From the beginning: my company had a website which was hacked and taken down eventually. We used locaweb as a host. Keep in mind that I’m completely new to this and still I am managing two websites (both of them giving me a headache) so I’m probably gonna ask stupid questions and not understand much. From what I understand, the domain is still the same, easyyourlife.com. My boss came to me and said “search some tutorials, make a website” so I did, on wordpress.com. I mapped the domain into wordpress, with a Business plan, a few days ago. I JUST found out that, for the kind of website I want, I need wordpress.org. But here’s the thing, I’ve downloaded the files. When I go into locaweb’s app installer, wordpress is already there. I don’t know if that’s the current website or the old one. When I open wordpress there, it shows me that the domain is active but doesn’t have any content. If you open the website easyyourlife.com you’ll see there IS content.
Anyway, so maybe the wordpress already installed there is for the old website. Right. So I click to install a new app, click to install wordpress, and it asks me for a DB user and password.
BUT when I created the website on wordpress, hosted at locaweb, I didn’t see DB information. When I try to find that out on FTP I can’t, because wordpress.com doesn’t allow access to FTP.
As you can see I’m completely at a loss with this, I don’t even know where to start.
I’d also like to know if I’ll have to pay again? I already pay locaweb for the hosting service and the business plan on wordpress.com.
Will I have to pay to migrate?