Newbie hack question (like a pre-sale question)

[Yosemite]

Hello world.
Congratulations for this forum.
I discovered the power and flexbility of this software, and I'm going to love it.....
I have an idea in my mind but is not so simple to type it....
mhhh.....let's try.

Actually I'm planning a php portal, oriented to customer services.
It should have a strong forum, (Vbulletin naturally with all the features), but also a personal account page, where users can:

- view and change the account type User- Supporter-etc.- (and so use their credit card for payments or donations);

- track some personal informations sent from administrator (but just not private messages), print and download it.

So my needs is to have every user, making just one registration from the home page and get just one user and pssw to use the forum or to log into the personal account, that must be something like the control panel of this board.

They make the registration just to enjoy the service offered so, in this way, they also have the freedom to post and partecipate the community.

So where I start from?

Thanks in advance and sorry if my questions are obvious.